Fix jsonschema version

Author: bastonero

aiida_lammps/validation/utils.py

@@ -19,4 +19,4 @@ def validate_against_schema(data: dict, filename: Union[str, os.PathLike]):
     with open(filename, encoding="utf8") as handler:
         schema = json.load(handler)
 
-    jsonschema.validate(schema=schema, instance=data)
+    jsonschema.validate(schema=schema, instance=data, cls=jsonschema.Draft4Validator)