[OpenMP][Tests][NFC] Mark unsupported OMPT tests for GCC

Codegen for some OpenMP directives is different from clang, so some
OMPT tests fail. As we don't expect GCC codegen to change significantly,
we mark the tests as unsupported for GCC.

OMPT Tests pass now with GCC 10, 11, 12

GitOrigin-RevId: 39a959eac793ee43008d6755206b6684fc11872d
2 files changed