[threading] Ignore Condition.locked in Python 3.15 (#16279)

Author: donbarbos

stdlib/@tests/stubtest_allowlists/py315.txt

@@ -23,7 +23,6 @@ importlib._abc.Loader.load_module
 importlib._bootstrap_external.NamespacePath
 importlib.resources._common.package_to_anchor
 mailbox._ProxyFile.__class_getitem__
-threading.Condition.locked
 
 # =============================================================
 # Allowlist entries that cannot or should not be fixed; >= 3.15
@@ -86,6 +85,9 @@ concurrent.interpreters._crossinterp.UnboundItem.singleton
 concurrent.interpreters._crossinterp.UNBOUND_ERROR
 concurrent.interpreters._crossinterp.UNBOUND_REMOVE
 
+# Condition functions are exported in __init__
+threading.Condition.locked
+
 # Assigning `__new__` causes `func` not to get recognized.
 functools.partialmethod.__new__