Update GitHub labeler action to v5

[QuLogic]

As the original schema did not have a version in the name, I'm a bit unsure whether I should add the version to the new one, the old one, or both, and/or make the non-versioned one the latest or vice-versa.

I also need to write up some tests.

[QuLogic]

Hmm, I don't quite understand what the compile is complaining about. It seems to work on my actual repo with pre-commit+check-jsonschema, and validates on https://www.jsonschemavalidator.net/ but maybe I'm missing something.

[QuLogic]

Ah, I found that pull-request-labeler.json is in the ajvNotStrictMode list, so I've added the new file there as well. I'm not sure why that is needed, as I can run ajv-cli validate on it and it passes.

I also found that I missed that file globs/branch names can be singular strings instead of array, so I've added that typing correction, and the example now pass.

[hyperupcall]

awesome, thanks

[QuLogic]

BTW, how does one find these alternate versions on https://www.schemastore.org/json/ ? If I search for 'label', I just get Pull Request Labeler, which is the old one. But https://json.schemastore.org/pull-request-labeler-5.json is online.

[hyperupcall]

Hmm, yeah it looks like the search feature does not include the recently added schemas. I'll have to look into it a bit more, but I think this issue is relatively low-priority.