Fix AttributeError when importing on Python 3.14

Author: hugovk

httpcore/__init__.py

@@ -136,5 +136,5 @@ def __init__(self, *args, **kwargs):  # type: ignore
 
 __locals = locals()
 for __name in __all__:
-    if not __name.startswith("__"):
+    if not __name.startswith(("__", "SOCKET_OPTION")):
         setattr(__locals[__name], "__module__", "httpcore")  # noqa