Add `./_events` to the `files:` parameter in `.github/workflows/linting.yaml:20`

[lparsons]

One thing that this PR illustrated is that ./_events should be added to the files: parameter in .github/workflows/linting.yaml:20.

That addition diagnosed two true positive typos that are still in place in main at this time.

Originally posted by @crd477 in #1430 (comment)