Ignore ASAN failure in UnitTestImpl (backport #3022)

[mergify]

The on_PR_mac_special_builds.yml workflow keeps failing due to an ASAN failure during unit testing. It looks like the problem is in the unit testing library, which isn't our code, so this PR fixes it by silencing the error.

This is an example of the error message:

7/7 Test #7: unitTests ........................Subprocess aborted***Exception:   0.82 sec
=================================================================
==8381==ERROR: AddressSanitizer: container-overflow on address 0x00010500123f at pc 0x0001005bd9d4 bp 0x00016f88ace0 sp 0x00016f88acd8
READ of size 1 at 0x00010500123f thread T0
    #0 0x1005bd9d0 in std::__1::vector<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>>::__base_destruct_at_end[abi:ue170006](std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>*)+0x1[20](https://github.com/Exiv2/exiv2/actions/runs/10228533538/job/28301173586#step:5:21) (unit_tests:arm64+0x10004d9d0)
    #1 0x1005bd680 in std::__1::vector<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>>::__destroy_vector::operator()[abi:ue170006]()+0x60 (unit_tests:arm64+0x10004d680)
    #2 0x1009e7ab4 in testing::internal::UnitTestImpl::GetTestSuite(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&, char const*, void (*)(), void (*)())+0x2d4 (unit_tests:arm64+0x100477ab4)
    #3 0x1009da834 in testing::internal::UnitTestImpl::AddTestInfo(void (*)(), void (*)(), testing::TestInfo*)+0xf8 (unit_tests:arm64+0x10046a834)
    #4 0x1009da6c8 in testing::internal::MakeAndRegisterTestInfo(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, char const*, char const*, char const*, testing::internal::CodeLocation, void const*, void (*)(), void (*)(), testing::internal::TestFactoryBase*)+0xfc (unit_tests:arm64+0x10046a6c8)
    #5 0x1007cb074 in _GLOBAL__sub_I_test_basicio.cpp+0x2c0 (unit_tests:arm64+0x10025b074)
    #6 0x194541058  (<unknown module>)
    #7 0x19457f304  (<unknown module>)
    #8 0x194572998 in invocation function for block in dyld3::MachOFile::forEachSection(void (dyld3::MachOFile::SectionInfo const&, bool, bool&) block_pointer) const+0x1ec (dyld:arm64e+0xfffffffffff9a998)
    #9 0x1945222f8  (<unknown module>)
    #10 0x19457192c in dyld3::MachOFile::forEachSection(void (dyld3::MachOFile::SectionInfo const&, bool, bool&) block_pointer) const+0xbc (dyld:arm64e+0xfffffffffff9992c)
    #11 0x19457ee18  (<unknown module>)
    #12 0x19453d06c  (<unknown module>)
    #13 0x194543610  (<unknown module>)
    #14 0x19453d458  (<unknown module>)
    #15 0x1945410e8  (<unknown module>)
    #16 0x19453d624  (<unknown module>)
    #17 0x1945604d4  (<unknown module>)
    #18 0x194526f78  (<unknown module>)
    #19 0x194525ed8  (<unknown module>)

0x00010500123f is located 47 bytes inside of 48-byte region [0x000105001[21](https://github.com/Exiv2/exiv2/actions/runs/10228533538/job/28301173586#step:5:22)0,0x000105001240)
allocated by thread T0 here:
    #0 0x101a6974c in wrap__Znwm+0x74 (libclang_rt.asan_osx_dynamic.dylib:arm64e+0x6174c)
    #1 0x1009eaf78 in std::__1::__allocation_result<std::__1::allocator_traits<std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>>::pointer> std::__1::__allocate_at_least[abi:ue170006]<std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>>(std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>&, unsigned long)+0x2c (unit_tests:arm64+0x10047af78)
    #2 0x1009eae2c in std::__1::vector<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>>::reserve(unsigned long)+0x58 (unit_tests:arm64+0x10047ae2c)
    #3 0x1009d3214 in testing::internal::(anonymous namespace)::UnitTestFilter::UnitTestFilter(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&)+0x8c (unit_tests:arm64+0x100463214)
    #4 0x1009e7908 in testing::internal::UnitTestImpl::GetTestSuite(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&, char const*, void (*)(), void (*)())+0x128 (unit_tests:arm64+0x100477908)
    #5 0x1009da834 in testing::internal::UnitTestImpl::AddTestInfo(void (*)(), void (*)(), testing::TestInfo*)+0xf8 (unit_tests:arm64+0x10046a834)
    #6 0x1009da6c8 in testing::internal::MakeAndRegisterTestInfo(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, char const*, char const*, char const*, testing::internal::CodeLocation, void const*, void (*)(), void (*)(), testing::internal::TestFactoryBase*)+0xfc (unit_tests:arm64+0x10046a6c8)
    #7 0x1007cb074 in _GLOBAL__sub_I_test_basicio.cpp+0x2c0 (unit_tests:arm64+0x10025b074)
    #8 0x194541058  (<unknown module>)
    #9 0x19457f304  (<unknown module>)
    #10 0x194572998 in invocation function for block in dyld3::MachOFile::forEachSection(void (dyld3::MachOFile::SectionInfo const&, bool, bool&) block_pointer) const+0x1ec (dyld:arm64e+0xfffffffffff9a998)
    #11 0x1945[22](https://github.com/Exiv2/exiv2/actions/runs/10228533538/job/28301173586#step:5:23)2f8  (<unknown module>)
    #12 0x19457192c in dyld3::MachOFile::forEachSection(void (dyld3::MachOFile::SectionInfo const&, bool, bool&) block_pointer) const+0xbc (dyld:arm64e+0xfffffffffff9992c)
    #13 0x19457ee18  (<unknown module>)
    #14 0x19453d06c  (<unknown module>)
    #15 0x194543610  (<unknown module>)
    #16 0x19453d458  (<unknown module>)
    #17 0x1945410e8  (<unknown module>)
    #18 0x19453d624  (<unknown module>)
    #19 0x1945604d4  (<unknown module>)
    #20 0x194526f78  (<unknown module>)
    #21 0x194525ed8  (<unknown module>)

HINT: if you don't care about these errors you may set ASAN_OPTIONS=detect_container_overflow=0.
If you suspect a false positive see also: https://github.com/google/sanitizers/wiki/AddressSanitizerContainerOverflow.
SUMMARY: AddressSanitizer: container-overflow (unit_tests:arm64+0x10004d9d0) in std::__1::vector<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>>>::__base_destruct_at_end[abi:ue170006](std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>*)+0x120
Shadow bytes around the buggy address:
  0x000105000f80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x000105001000: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x000105001080: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x000105001100: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x000105001180: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x000105001200: fa fa fc fc fc fc fc[fc]fa fa fd fd fd fd fd fd
  0x000105001[28](https://github.com/Exiv2/exiv2/actions/runs/10228533538/job/28301173586#step:5:29)0: fa fa 00 00 00 00 00 00 fa fa 00 00 00 00 00 00
  0x000105001300: fa fa 00 00 00 00 00 fa fa fa fd fd fd fd fd fa
  0x000105001380: fa fa fd fd fd fd fd fa fa fa 00 00 00 00 00 00
  0x000105001400: fa fa 00 00 00 00 00 00 fa fa 00 00 00 00 00 00
  0x000105001480: fa fa 00 00 00 00 00 00 fa fa 00 00 00 00 00 00
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07 
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
==8[38](https://github.com/Exiv2/exiv2/actions/runs/10228533538/job/28301173586#step:5:39)1==ABORTING

Errors while running CTest

86% tests passed, 1 tests failed out of 7

Total Test time (real) = 143.89 sec

The following tests FAILED:
	  7 - unitTests (Subprocess aborted)
Error: Process completed with exit code 8.
```<hr>This is an automatic backport of pull request #3022 done by [Mergify](https://mergify.com).