Switch to custom keyword_dataclasses.py

Whenever non-default arguments follow default arguments, they are marked
as keyword-only: f(a=1, *, b)

ovgenpy/config.py

@@ -1,7 +1,7 @@
 from io import StringIO
 from typing import ClassVar
 
-from dataclasses import dataclass, fields
+from ovgenpy.utils.keyword_dataclasses import dataclass, fields
 from ruamel.yaml import yaml_object, YAML