[CI] Test All Projects On Workflow Changes
This patch makes it so that we actually run all the tests when we touch
the workflow file in .github/workflows/premerge.yaml. Before this we
would not run any tests and it was annoying to have to manually touch a
file to get something to trigger.
Reviewers: Keenuts, lnihlen, cmtice, dschuff, gburgessiv
Reviewed By: gburgessiv
Pull Request: https://github.com/llvm/llvm-project/pull/150250
