test_concurrent_futures: Fix unneeded/confusing format call (GH-93119)

Added in 339fd46cb764277cbbdc3e78dcc5b45b156bb6ae - but as noted in a comment, the test only tests ThreadPoolExecutor.
(cherry picked from commit 3f2dd0a7c0b1a5112f2164dce78fcfaa0c4b39c7)

Co-authored-by: Florian Bruhin <me@the-compiler.org>

Miss Islington (bot) committed 3y ago

fbd24068c2c82004297f3d267509f878e70a8730

Parent: 7733aa0

Committed by GitHub <noreply@github.com> on 7/19/2022, 2:42:19 AM