tests in tests/common/util.rs fails on OpenBSD 7.5

[jadijadi]

The cargo test fails on OpenBSD due to not supporting xattrs.

failures:                                                                                                                
                                                            
---- common::util::tests::test_compare_xattrs stdout ----   
thread 'common::util::tests::test_compare_xattrs' panicked at tests/common/util.rs:3628:56:                              
called `Result::unwrap()` on an `Err` value: Custom { kind: Unsupported, error: UnsupportedPlatformError }               
                                                                                                                         
                                                                                                                         
failures:                                                                                                                
    common::util::tests::test_compare_xattrs    

There are several other failing tests on utils section on OpenBSD but this one is kind of more important because its in the tests/common/util.rs and when it breaks tests do not continue to by-util section.

[jadijadi]

Opening this to prevent creating a closely related case.
After remove the actual compare_xattrs based on PRs discussions (which looks like a good decision), OpenBSD cargo test for mv and cp also breaks because they do have tests based on that function. So I will send another PR to add the target_os is not openbsd condition to these tests too.