fix context may be None (#696)

Co-authored-by: Adrian Garcia Badaracco <[email protected]>

Author: FynnBe

pydantic_core/core_schema.py

@@ -144,7 +144,7 @@ class ValidationInfo(Protocol):
     """
 
     @property
-    def context(self) -> Dict[str, Any]:
+    def context(self) -> Any | None:
         """Current validation context."""
         ...