Fix typo

Co-authored-by: Daniel King <[email protected]>

llmfoundry/callbacks/hf_checkpointer.py

@@ -242,7 +242,7 @@ def run_event(self, event: Event, state: State, logger: Logger) -> None:
                 wait_time = time.time() - wait_start
                 if wait_time > timeout:
                     raise TimeoutError(
-                        f'Waited {wait_time} seconds for child processes to complete. Exceed timeout of {timeout} seconds.'
+                        f'Waited {wait_time} seconds for child processes to complete. Exceeded timeout of {timeout} seconds.'
                     )
                 time.sleep(2)