Big diff: use lower-case list and dict (#5888)

stdlib/rlcompleter.pyi

@@ -1,5 +1,5 @@
-from typing import Any, Dict
+from typing import Any
 
 class Completer:
-    def __init__(self, namespace: Dict[str, Any] | None = ...) -> None: ...
+    def __init__(self, namespace: dict[str, Any] | None = ...) -> None: ...
     def complete(self, text: str, state: int) -> str | None: ...