Add missing __slots__ to third-party packages (#15454)

stubs/JACK-Client/jack/__init__.pyi

@@ -271,6 +271,7 @@ class RingBuffer:
     def size(self) -> int: ...
 
 class Status:
+    __slots__ = "_code"
     def __init__(self, code: int) -> None: ...
     @property
     def failure(self) -> bool: ...
@@ -300,6 +301,7 @@ class Status:
     def client_zombie(self) -> bool: ...
 
 class TransportState:
+    __slots__ = "_code"
     def __init__(self, code: int) -> None: ...
     def __eq__(self, other: object) -> bool: ...
     def __hash__(self) -> int: ...