Fix typo in message from assert statement (GH-21283)


The error message was missing space between the action "acquire" and "_wait_semaphore" which is an attribute for instances of Condition.
(cherry picked from commit 99c0ee3c893bb99fd98a97084fc386ce2911eb64)

Co-authored-by: Allen <64019758+aboddie@users.noreply.github.com>
1 file changed