[feat]: add gitlab-ci.yaml coverage

[ioggstream]

I expect

• gitlab-ci.yaml to highlight code coverage

Instead

• no code coverage

Notes

see https://docs.gitlab.com/ee/ci/testing/test_coverage_visualization/

job:
 ...
# From: https://docs.gitlab.com/ee/ci/testing/code_coverage.html#test-coverage-examples
  coverage: /TOTAL.*? (100(?:\.0+)?\%|[1-9]?\d(?:\.\d+)?\%)$/

  # From: https://docs.gitlab.com/ee/ci/testing/test_coverage_visualization/cobertura.html#python-example
  artifacts:
    reports:
      coverage_report:
        coverage_format: cobertura
        path: coverage.xml

[ioggstream]

cc: @ilovelinux

[ilovelinux]

The syntax is highly coupled with the actual test suite. As written in the GitLab documentation, that regex is compatible only with pytest-cov.

Same for the artifacts. I don't have any ideas about how to implement it.