Describe the bug

When triggering off a pull_request_target event, the GitHub Action successfully looks up the signature of the committer, but then fails with error "Unable to locate this workflow's ID in this repository, can't trigger job..". This renders the status of the commit as failed and blocks merging of the PR.

I suspect that pull_request_target may need adding to this check in addition to pull_request:

To Reproduce

Steps to reproduce the behavior:

1. Trigger the GHA using pull_request_target as instructed in the README
2. Open a PR, sign, and you will experience this error

Expected behavior

The status check passes because all committers have signed the CLA.