fix quality

Author: dwyatte

tests/fixtures/fsspec.py

@@ -69,7 +69,7 @@ def modified(self, path):
     @classmethod
     def _strip_protocol(cls, path):
         path = stringify_path(path)
-        if path.startswith(f"mock://"):
+        if path.startswith("mock://"):
             path = path[7:]
         return path