Add __slots__ to third-party packages using stubdefaulter (#14619)

stubs/paramiko/paramiko/transport.pyi

@@ -175,6 +175,7 @@ class Transport(Thread, ClosingContextManager):
     def run(self) -> None: ...
 
 class SecurityOptions:
+    __slots__ = "_transport"
     def __init__(self, transport: Transport) -> None: ...
     @property
     def ciphers(self) -> Sequence[str]: ...