[3.14] gh-135329: Remove flaky test_repl_eio test (gh-145932) (#146028)

The test doesn't actually test any pyrepl code (it runs Python with -S)
and has a race condition that causes intermittent timeouts on CI.
(cherry picked from commit e18abc6a1f1b60434b529d4c1ff4855acde0fd13)

Co-authored-by: Sam Gross <colesbury@gmail.com>