pr-subscribers-clang:frontend does not exist

This pages:

https://github.com/llvm/llvm-project/blob/main/.github/new-prs-labeler.yml

says there is a pr-subscribers-clang:frontend but there is not:

https://github.com/orgs/llvm/teams?query=pr-subscribers-clang%3Afrontend

Start with .github/new-prs-labeler.yml and compare the pr-subscribers-clang:frontend reference with the available LLVM teams linked in the issue. Determine the appropriate configuration correction, then verify that the labeler file no longer references a nonexistent team and that its syntax remains valid.

Written by the indexing model from the issue text.