module: update rope to version 0.21

Updates the requirements on [rope](https://github.com/python-rope/rope) to permit the latest version (#52).
- [Release notes](https://github.com/python-rope/rope/releases)
- [Changelog](https://github.com/python-rope/rope/blob/master/CHANGELOG.md)
- [Commits](https://github.com/python-rope/rope/compare/0.20.0...0.21.0)

---
updated-dependencies:
- dependency-name: rope
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

pyproject.toml

@@ -18,7 +18,7 @@ requests = "~2.26"
 [tool.poetry.dev-dependencies]
 mypy = "0.910"
 pylint = "~2.11"
-rope = "~0.20"
+rope = "~0.21"
 types-PyYAML = "~6.0"
 types-requests = "~2.25"
 yapf = "~0.31"