[llvm-branch-commits] [CI] Test All Projects On Workflow Changes (PR #150250)

[Aiden Grossman via llvm-branch-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/150250

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.