GitHub Actions displays frontend lints to every PR

[jtgeibel]

Since GitHub Actions was enabled in #1942, the 8 lints detected by npm run lint:js are detected by GitHub and shown on every PR.

For example, PR 2031 touches unrelated files and has a beta "Unchanged files with check annotations" at the bottom of the file change list.

Alternatively, PR 2039 touches a file with a warning and several notifications appear inline with the diff.

I don't know how difficult it is to address those lints, so for now I'm suggesting that we temporarily remove this check from our configuration for GH Actions.

cc @Turbo87

[Turbo87]

@jtgeibel we can ignore the checks for those specific offending lines using a particular ESLint comment. I'll open a PR to get this fixed. Thanks for bringing it to my attention 👍