Gitlab-languages

Provide proper PyPI data

Chore

Make sure to install poetry in CI

**Full Changelog**: https://github.com/max-wittig/gitlab-languages/compare/v2.1.0...v2.3.1

Maintenance

* 1093adf chore: fix poetry lock file
* 0ad6c52 chore: switch to GitHub actions
* eee4469 refactor: modernize project
* 434212f Merge pull request 17 from max-wittig/dependabot/pip/certifi-2022.12.7
* d7b1319 chore(deps): bump certifi from 2021.10.8 to 2022.12.7
* e8f260b chore: bump all dependencies

* Use keyset pagination and prevent crash, because `X-Total` doesn't exist anymore

* Switch to latest python-gitlab so keyset pagination can be used
* Refactor project to use poetry instead of pipenv

* The amount of workers can now be customized with the `WORKER_COUNT` environment variable