Clean Gitlab Comment Reporter doc

[LBeaulaton]

Fixes #2423

Proposed Changes

1. delete GITLAB_API_URL and GITLAB_SERVER_URL in the reporter doc

Readiness Checklist

Author/Contributor

• Add entry to the CHANGELOG listing the change and linking to the corresponding issue (if appropriate)
• If documentation is needed for this change, has that been included in this pull request

Reviewing Maintainer

• Label as breaking if this is a large fundamental change
• Label as either automation, bug, documentation, enhancement, infrastructure, or performance

[echoix]

Thanks for your quick PR! Since we just released a new version, would you mind placing your new changelog entry above in the "beta" section, once merging (or rebasing) back the main branch in the PR?

[nvuillam]

Thanks a lot :)