[multiprocessing] Update BaseListProxy, multiprocessing.managers.list (#15070)

Author: guoci

stdlib/@tests/stubtest_allowlists/py314.txt

@@ -3,6 +3,7 @@
 # ====================================================================
 
 multiprocessing.managers.BaseListProxy.clear
+# inspect.signature gives the wrong signature
 multiprocessing.managers.BaseListProxy.copy
 multiprocessing.managers.DictProxy.__ior__
 multiprocessing.managers._BaseDictProxy.__ior__

stdlib/multiprocessing/managers.pyi

@@ -192,6 +192,8 @@ class BaseListProxy(BaseProxy, MutableSequence[_T]):
     def count(self, value: _T, /) -> int: ...
     def insert(self, index: SupportsIndex, object: _T, /) -> None: ...
     def remove(self, value: _T, /) -> None: ...
+    if sys.version_info >= (3, 14):
+        def copy(self) -> list[_T]: ...
     # Use BaseListProxy[SupportsRichComparisonT] for the first overload rather than [SupportsRichComparison]
     # to work around invariance
     @overload
@@ -326,8 +328,9 @@ class SyncManager(BaseManager):
     def dict(self, iterable: Iterable[list[str]], /) -> DictProxy[str, str]: ...
     @overload
     def dict(self, iterable: Iterable[list[bytes]], /) -> DictProxy[bytes, bytes]: ...
+    # Overloads are copied from builtins.list.__init__
     @overload
-    def list(self, sequence: Sequence[_T], /) -> ListProxy[_T]: ...
+    def list(self, iterable: Iterable[_T], /) -> ListProxy[_T]: ...
     @overload
     def list(self) -> ListProxy[Any]: ...
     if sys.version_info >= (3, 14):