build(deps): bump msgpack-c to v6.0.0 (neovim#22522)

* Remove C++ requirement if test is disabled
* Change CMake package name of C library to msgpack-c
* Unified all C package, library, cmake, tarball name become msgpack-c.

cmake.deps/CMakeLists.txt

@@ -134,8 +134,8 @@ set_directory_properties(PROPERTIES EP_PREFIX "${DEPS_BUILD_DIR}")
 set(LIBUV_URL https://github.com/libuv/libuv/archive/62c2374a8c005ce9e42088965f8f8af2532c177b.tar.gz)
 set(LIBUV_SHA256 c7e89137da65a1cb550ba96b892dfeeabea982bf33b9237bcf9bbcd90f2e70a1)
 
-set(MSGPACK_URL https://github.com/msgpack/msgpack-c/releases/download/c-4.0.0/msgpack-c-4.0.0.tar.gz)
-set(MSGPACK_SHA256 420fe35e7572f2a168d17e660ef981a589c9cbe77faa25eb34a520e1fcc032c8)
+set(MSGPACK_URL https://github.com/msgpack/msgpack-c/releases/download/c-6.0.0/msgpack-c-6.0.0.tar.gz)
+set(MSGPACK_SHA256 3654f5e2c652dc52e0a993e270bb57d5702b262703f03771c152bba51602aeba)
 
 # https://github.com/LuaJIT/LuaJIT/tree/v2.1
 set(LUAJIT_URL https://github.com/LuaJIT/LuaJIT/archive/505e2c03de35e2718eef0d2d3660712e06dadf1f.tar.gz)

cmake/FindMsgpack.cmake

@@ -10,14 +10,7 @@ else()
   set(MSGPACK_VERSION_STRING)
 endif()
 
-if(MSVC)
-  # The import library for the msgpack DLL has a different name
-  list(APPEND MSGPACK_NAMES msgpackc_import)
-else()
-  list(APPEND MSGPACK_NAMES msgpackc msgpack)
-endif()
-
-find_library(MSGPACK_LIBRARY NAMES ${MSGPACK_NAMES}
+find_library(MSGPACK_LIBRARY NAMES msgpackc msgpack msgpackc_import msgpack-c
   NAMES_PER_DIR)
 
 mark_as_advanced(MSGPACK_INCLUDE_DIR MSGPACK_LIBRARY)