Fix lint errors: remove unused variable and add raw string prefixes

- Remove unused 'crew' variable in test_hierarchical_crew_does_not_propagate_agent_tools_to_manager (F841)
- Add raw string prefixes to regex patterns to comply with RUF043 linting rule
- Pre-existing RUF043 errors in changed files were blocking PR, so fixed them

Co-Authored-By: João <joao@crewai.com>

tests/test_task.py

@@ -1222,7 +1222,7 @@ def test_create_directory_false():
     assert not resolved_dir.exists()
 
     with pytest.raises(
-        RuntimeError, match="Directory .* does not exist and create_directory is False"
+        RuntimeError, match=r"Directory .* does not exist and create_directory is False"
     ):
         task._save_file("test content")