[gunicorn] Fix ssl_context function return type annotation

Author: eugeneliukindev

stubs/gunicorn/gunicorn/sock.pyi

@@ -2,7 +2,7 @@ import socket
 from _typeshed import Incomplete
 from collections.abc import Iterable
 from logging import Logger
-from ssl import SSLSocket
+from ssl import SSLSocket, SSLContext
 from typing import Any, ClassVar, Literal, SupportsIndex, override
 
 from .config import Config
@@ -37,5 +37,5 @@ class UnixSocket(BaseSocket):
 
 def create_sockets(conf: Config, log: Logger, fds: Iterable[SupportsIndex] | None = None) -> list[BaseSocket]: ...
 def close_sockets(listeners: Iterable[socket.socket], unlink: bool = True) -> None: ...
-def ssl_context(conf: Config) -> Incomplete: ...
+def ssl_context(conf: Config) -> SSLContext: ...
 def ssl_wrap_socket(sock: socket.socket, conf: Config) -> SSLSocket: ...