sqlite3: allow passing None for the func parameter of create_function (#8728)

Author: shawnbrown

stdlib/sqlite3/dbapi2.pyi

@@ -318,10 +318,10 @@ class Connection:
     def create_collation(self, __name: str, __callback: Callable[[str, str], int | SupportsIndex] | None) -> None: ...
     if sys.version_info >= (3, 8):
         def create_function(
-            self, name: str, narg: int, func: Callable[..., _SqliteData], *, deterministic: bool = ...
+            self, name: str, narg: int, func: Callable[..., _SqliteData] | None, *, deterministic: bool = ...
         ) -> None: ...
     else:
-        def create_function(self, name: str, num_params: int, func: Callable[..., _SqliteData]) -> None: ...
+        def create_function(self, name: str, num_params: int, func: Callable[..., _SqliteData] | None) -> None: ...
 
     @overload
     def cursor(self, cursorClass: None = ...) -> Cursor: ...