core[patch]: fix beta, deprecated typing (#18877)

**Description:** 

While not technically incorrect, the TypeVar used for the `@beta`
decorator prevented pyright (and thus most vscode users) from correctly
seeing the types of functions/classes decorated with `@beta`.

This is in part due to a small bug in pyright
(https://github.com/microsoft/pyright/issues/7448 ) - however, the
`Type` bound in the typevar `C = TypeVar("C", Type, Callable)` is not
doing anything - classes are `Callables` by default, so by my
understanding binding to `Type` does not actually provide any more
safety - the modified annotation still works correctly for both
functions, properties, and classes.

---------

Co-authored-by: Bagatur <22008038+baskaryan@users.noreply.github.com>
Co-authored-by: Bagatur <baskaryan@gmail.com>

libs/core/tests/unit_tests/prompts/test_structured.py

@@ -23,7 +23,9 @@ def _fake_runnable(
 class FakeStructuredChatModel(FakeListChatModel):
     """Fake ChatModel for testing purposes."""
 
-    def with_structured_output(self, schema: Union[Dict, Type[BaseModel]]) -> Runnable:
+    def with_structured_output(
+        self, schema: Union[Dict, Type[BaseModel]], **kwargs: Any
+    ) -> Runnable:
         return RunnableLambda(partial(_fake_runnable, schema))
 
     @property