Apply ruff/pyupgrade rule UP031

UP031 Use format specifiers instead of percent format

Author: DimitriPapadopoulos

uvloop/__init__.py

@@ -204,8 +204,7 @@ def get_event_loop(self) -> _AbstractEventLoop:
             """
             if self._local._loop is None:
                 raise RuntimeError(
-                    'There is no current event loop in thread %r.'
-                    % threading.current_thread().name
+                    f'There is no current event loop in thread {threading.current_thread().name!r}.'
                 )
 
             return self._local._loop