[logging] Use threading.RLock for logging.Handler.lock (#16022)

CPython's logging.Handler has used an RLock (not a Lock) since
Python 2.5, and RLock is not a subclass of Lock, so the stub type
was inaccurate.

Author: pctablet505

stdlib/logging/__init__.pyi

@@ -245,7 +245,7 @@ NOTSET: Final = 0
 class Handler(Filterer):
     level: int  # undocumented
     formatter: Formatter | None  # undocumented
-    lock: threading.Lock | None  # undocumented
+    lock: threading.RLock | None  # undocumented
     name: str | None  # undocumented
     def __init__(self, level: _Level = 0) -> None: ...
     def get_name(self) -> str: ...  # undocumented