pipeline: remove coveralls ("422 Client Error: Unprocessable Entity for url: https://coveralls.io/api/v1/jobs", `pytest --cov-fail-under=100 …` in place)

https://github.com/fphammerle/python-manchester-code/commit/81a66a970575486b841ca3d919c4b8f9e99f96ac
https://github.com/fphammerle/wireless-sensor-mqtt/commit/8316bd7766bc6ea49a864262eaa2869d161bfada

.github/workflows/python.yml

@@ -55,12 +55,3 @@ jobs:
     # https://github.com/PyCQA/pylint/issues/352
     - run: pipenv run pylint tests/*
     - run: pipenv run mypy "$(cat *.egg-info/top_level.txt)" tests
-    # >=2.1.0 to support GITHUB_TOKEN
-    # COVERALLS_REPO_TOKEN required manual configuration of secret
-    # https://github.com/TheKevJames/coveralls-python/commit/f597109b62fadaf900af79d4f08a7debee5229e2
-    - run: pip install 'coveralls>=2.1.0,<4'
-    - run: coveralls
-      env:
-        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        # https://github.com/TheKevJames/coveralls-python/issues/240#issuecomment-758336355
-        COVERALLS_SERVICE_NAME: github