[llvm] [YAML][NFC] precommit wrong test case (PR #131782)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `openmp-offload-sles-build-only` running on `rocm-worker-hw-04-sles` while building `llvm` at step 8 "Add check check-llvm".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/140/builds/19747

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 8 (Add check check-llvm) failure: test (failure)
...
[686/699] Linking CXX executable unittests/DebugInfo/DWARF/DebugInfoDWARFTests
[687/699] Linking CXX executable unittests/Passes/Plugins/PluginsTests
[688/699] Linking CXX executable unittests/ExecutionEngine/MCJIT/MCJITTests
[689/699] Linking CXX executable unittests/Target/X86/X86Tests
[690/699] Linking CXX executable unittests/MI/MITests
[691/699] Linking CXX executable unittests/tools/llvm-mca/LLVMMCATests
[692/699] Linking CXX executable unittests/MIR/MIRTests
[693/699] Linking CXX executable unittests/Transforms/Scalar/ScalarTests
[694/699] Linking CXX executable unittests/tools/llvm-exegesis/LLVMExegesisTests
[695/699] Building CXX object unittests/Support/CMakeFiles/SupportTests.dir/YAMLIOTest.cpp.o
FAILED: unittests/Support/CMakeFiles/SupportTests.dir/YAMLIOTest.cpp.o 
ccache /usr/bin/c++ -DGTEST_HAS_RTTI=0 -DLLVM_BUILD_STATIC -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Iunittests/Support -I/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/unittests/Support -Iinclude -I/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/include -I/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/third-party/unittest/googletest/include -I/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/third-party/unittest/googlemock/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-uninitialized -Wno-nonnull -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wno-comment -Wno-misleading-indentation -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG  -Wno-dangling-else -Wno-variadic-macros -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -Wno-suggest-override -std=c++1z -MD -MT unittests/Support/CMakeFiles/SupportTests.dir/YAMLIOTest.cpp.o -MF unittests/Support/CMakeFiles/SupportTests.dir/YAMLIOTest.cpp.o.d -o unittests/Support/CMakeFiles/SupportTests.dir/YAMLIOTest.cpp.o -c /home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/unittests/Support/YAMLIOTest.cpp
/home/botworker/bbot/builds/openmp-offload-sles-build/llvm.src/llvm/unittests/Support/YAMLIOTest.cpp:1280:20: error: explicit specialization of ‘template<class T> struct llvm::yaml::MappingTraits’ outside its namespace must use a nested-name-specifier [-fpermissive]
 template <> struct MappingTraits<V> {
                    ^~~~~~~~~~~~~~~~
[696/699] Linking CXX executable unittests/Target/TargetMachineCTests
[697/699] Linking CXX executable unittests/Target/AMDGPU/AMDGPUTests
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/131782