croniter: add new encoding parameter to is_valid (#11808)

stubs/croniter/croniter/croniter.pyi

@@ -103,7 +103,7 @@ class croniter(Iterator[Any]):
     @classmethod
     def expand(cls, expr_format: str, hash_id: bytes | None = None) -> tuple[list[list[str]], dict[str, set[int]]]: ...
     @classmethod
-    def is_valid(cls, expression: str, hash_id: bytes | None = None) -> bool: ...
+    def is_valid(cls, expression: str, hash_id: bytes | None = None, encoding: str = "UTF-8") -> bool: ...
     @classmethod
     def match(cls, cron_expression: str, testdate: float | datetime.datetime | None, day_or: bool = True) -> bool: ...
     @classmethod