chore(deps): remove obsolete dataclasses dependency (#674)

Author: afuetterer

pyproject.toml

@@ -29,7 +29,6 @@ dependencies = [
   "python-gitlab>=2,<4",
   "tomlkit~=0.10",
   "dotty-dict>=1.3.0,<2",
-  "dataclasses==0.8; python_version < '3.7.0'",
   "importlib-resources==5.7",
   "pydantic>=1.10.2,<2",
   "rich>=12.5.1",