Auto merge of #143035 - ywxt:less-work-steal, r=oli-obk

Only work-steal in the main loop for rustc_thread_pool

This PR is a replica of <rust-lang/rustc-rayon#12> that only retained work-steal in the main loop for rustc_thread_pool.

r? `@oli-obk`

cc `@SparrowLii` `@Zoxc` `@cuviper`

Updates rust-lang/rust#113349

Author: bors