feat: use CI_JOB_TOKEN if no PAT provided

[superewald]

This PR adds a feature to use the CI_JOB_TOKEN provided for Gitlab CI jobs by default if no PAT was configured (as requested in go-semantic-release/semantic-release#141).

implementation

• If no PAT is provided with the config or env vars the plugin defaults to use the CI_JOB_TOKEN and the gitlab.JobClient instead
• GetCommit and GetReleases will fall back to the Git Provider implementations because the job token can't access private repository informations through the API.

tests

I ran tests on a public and private repository in gitlab, both of them succeeded. Probably adding unit tests would be good but I can't think of a good way of testing the feature outside the gitlab ci.

[superewald]

@christophwitzko are unit tests for this feature demanded ? If so I would need a simple guideline what exactly to test

[cliedeman]

Thanks @superewald looks good to me.

I would also like @christophwitzko to weigh in as he wrote the git provider.

On tests: I agree that unit tests are probably uncessary.

[christophwitzko]

Thank you @superewald for implementing this. I left some smaller comments. ☺️

[superewald]

I'm happy to contribute to this awesome project :)
I have some unrelated questions on the other repos but actually don't want to spam the issues, do we have a place to discuss the project or should I go with issues ?

[christophwitzko]

Glad to hear! ☺️😎
Yes, I think creating issues is currently the best way to do so.

[christophwitzko]

It seems that the Windows build is failing because of some gcc errors. Will hopefully have time to take a look later today. (probably we have to add CGO_ENABLED=0 😅)

[superewald]

It seems that the Windows build is failing because of some gcc errors. Will hopefully have time to take a look later today. (probably we have to add CGO_ENABLED=0 😅)

It's a known bug with GO < 1.20 and windows 2022 image (golang/go#51007). There are 3 possible fixes:

1. disable CGO (not sure if thats okey due to dependencies)
2. use GO > 1.20
3. use windows 2019 image if go < 1.20

[christophwitzko]

I updated go and rebased your pr onto master. 🙏
https://github.com/go-semantic-release/provider-gitlab/releases/tag/v1.13.0

Thanks again for your contribution 👍