Upgrade to eslint v9

[kewisch]

I've cleaned up some of the rules already in eslint:recommended and migrated to eslint v9

[coveralls]

Pull Request Test Coverage Report for Build 8632574243

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 98.024%

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Totals
Change from base Build 8627216459:	0.0%
Covered Lines:	9287
Relevant Lines:	9458

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💛 - Coveralls