[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

mypy/dmypy_server.py

@@ -732,7 +732,7 @@ def _seen_and_ancestors(self, seen: set[str]) -> set[str]:
         """
         seen_paths = seen.copy()
         for module_path in seen:
-            while module_path := module_path.rpartition('.')[0]:
+            while module_path := module_path.rpartition(".")[0]:
                 if module_path in seen_paths:
                     break
                 else: