Do not run rubocop on non-CRuby

[eregon]

It does not seem useful (redundant with running it on CRuby), makes builds slower, and also sometimes makes builds fail: https://github.com/puma/puma/runs/4047984193?check_suite_focus=true

[dentarg]

I agree

[dentarg]

I'll note that this has been discussed before at #2198 (comment) but I think we prefer green (and faster) tests over keeping it the same.

[dentarg]

sometimes makes builds fail: https://github.com/puma/puma/runs/4047984193?check_suite_focus=true

Do you have any idea as to why @eregon?

[eregon]

I'll note that this has been discussed before at #2198 (comment) but I think we prefer green (and faster) tests over keeping it the same.

Looks like the conclusion was the same: only run it on CRuby: https://github.com/puma/puma/pull/2198/files#diff-ce0dee93a528f6c7648f4cd671a3ec7be6a80f976c88f3aa1c322b7a80828fbaR46

Do you have any idea as to why @eregon?

Not sure, maybe it's a out of memory error. It seems GitHub Actions is really terse when a process gets killed.

[nateberkopec]

Thanks for all fixes @eregon