[stdlib] Add locked method threading.Condition

Author: guoci

stdlib/threading.pyi

@@ -144,6 +144,8 @@ class Condition:
     ) -> None: ...
     def acquire(self, blocking: bool = True, timeout: float = -1) -> bool: ...
     def release(self) -> None: ...
+    if sys.version_info >= (3, 14):
+        def locked(self) -> bool: ...
     def wait(self, timeout: float | None = None) -> bool: ...
     def wait_for(self, predicate: Callable[[], _T], timeout: float | None = None) -> _T: ...
     def notify(self, n: int = 1) -> None: ...