Revert "Merge pull request #28283 from y-yagi/silence_puma_startup_me…
This reverts commit 0d73f91, reversing
changes made to 21ff8a4.
We don't want to silence Puma because it's start up messages can be
useful (to see threads, port etc). #28109 was instead fixed by not
running system tests by defaul with `bin/rails test` in #28286.