Add missing py.typed in autogen_ext, fix type issue in core (microsoft#4993)

Author: jackgerrits

python/packages/autogen-core/src/autogen_core/_component_config.py

@@ -2,7 +2,7 @@
 
 import importlib
 import warnings
-from typing import Any, ClassVar, Dict, Generic, Literal, Protocol, Type, cast, overload, runtime_checkable
+from typing import Any, ClassVar, Dict, Generic, List, Literal, Protocol, Type, cast, overload, runtime_checkable
 
 from pydantic import BaseModel
 from typing_extensions import Self, TypeVar
@@ -243,9 +243,9 @@ def _from_config(cls, config: Config) -> MyComponent:
                 return cls(value=config.value)
     """
 
-    required_class_vars = ["component_config_schema", "component_type"]
+    required_class_vars: ClassVar[List[str]] = ["component_config_schema", "component_type"]
 
-    def __init_subclass__(cls, **kwargs: Any):
+    def __init_subclass__(cls, **kwargs: Any) -> None:
         super().__init_subclass__(**kwargs)
 
         # TODO: validate provider is loadable