Use correct JSON schema dialect for param validation (#15483)

src/prefect/_internal/schemas/validators.py

@@ -70,7 +70,7 @@ def validate_schema(schema: dict):
     try:
         if schema is not None:
             # Most closely matches the schemas generated by pydantic
-            jsonschema.Draft4Validator.check_schema(schema)
+            jsonschema.Draft202012Validator.check_schema(schema)
     except jsonschema.SchemaError as exc:
         raise ValueError(
             "The provided schema is not a valid json schema. Schema error:"