context: https://mongodb.slack.com/archives/C0V896UV8/p1748023222561719

We don't error on the evergreen validation warnings like:

WARNING: buildvariant 'enterprise-rhel8-debug-tsan-required' has unmatched criteria: 'compile_test_parallel_unittest_stream_TG'

I assume this is because we expect the tag-based criteria to come up empty sometimes.

https://github.com/10gen/mongo/blob/0fe0b717d121ba953c2ed2a32b83e3c5125a514b/buildscripts/validate_evg_project_config.py#L23