feat: detect pipeline with status success-with-warnings

[seyguai]

Use pipeline detailed status to expose if the pipeline was successful with a warning (job with allow_failure: true)

Attempt to implement suggestion from #123

[mvisonneau]

thanks for the feature @seyguai !

[armingerten]

Does this feature require a specific GitLab version or configuration of the exporter?

I just updated the exporter to v0.5.10 but it does not seem to export any gitlab_ci_pipeline_status metric for projects in status "success-with-warnings".

I just checked the API and I get the following output (I removed some personal information):

{
  "id": 6592653,
  "iid": 1138,
  "project_id": 10465,
  "sha": "0480f5e44dc29c21f2c497c1d05aa0d9a23fc8af",
  "ref": "main",
  "status": "success",
  "source": "push",
  "created_at": "2025-01-15T09:31:04.806Z",
  "updated_at": "2025-01-15T09:31:21.268Z",
  "web_url": "*****",
  "before_sha": "d1da73c9e4ca3a91b444e36a87f64ff21895bd5a",
  "tag": false,
  "yaml_errors": null,
  "user": { ***** },
  "started_at": "2025-01-15T09:31:07.376Z",
  "finished_at": "2025-01-15T09:31:21.256Z",
  "committed_at": null,
  "duration": 13,
  "queued_duration": 2,
  "coverage": null,
  "detailed_status": {
    "icon": "status_warning",
    "text": "Warning",
    "label": "passed with warnings",
    "group": "success-with-warnings",
    "tooltip": "passed",
    "has_details": true,
    "details_path": "*****",
    "illustration": null,
    "favicon": "*****"
  },
  "name": null
}

[seyguai]

I tried it myself, and could find any pipelines with such warning. However, I noticed that the pipeline that should have such status were no longer exposed. So there is a bug.

I managed to test, fix & improve it with this PR: #990