Rollup merge of #152845 - jieyouxu:split-tidy-from-pr-test-jobs, r=marcoieni

Skip `tidy` in PR CI jobs not dedicated to running `tidy`

This is both:

1. Redundant, since PR CI has a dedicated `tidy` job which runs in parallel and doesn't early-cancel other PR CI jobs
2. A contributor roadblock, because tidy failures in one test jobs block further failures from other test jobs being revealed.

(2) defeats the parallel-but-not-early-cancelling reason of the separate `tidy` job in the first place.

This PR skips tidy from being run in PR CI jobs that are not dedicated to running `tidy` (i.e. the non-`tidy` CI jobs).

Fixes rust-lang/rust#148932.

Author: JonathanBrouwer