Auto merge of #140786 - Kobzol:try-builds-no-deny-warnings, r=jieyouxu

Do not deny warnings in "fast" try builds

When we do the classic ``@bors` try` build without specifying `try-job` in the PR description, we want to get a compiler toolchain for perf./crater/local experimentation as fast as possible. We don't run any tests in that case, so it seems reasonable to also ignore warnings.

Fixes: rust-lang/rust#140753

r? `@jieyouxu`

try-job: dist-x86_64-linux

Author: bors