GitLab sync fails if project doesn't have CI/CD enabled

[thomas-gerber]

Describe the bug
When a project does not have CI/CD activated, the sync will fail because of 403 API errors during the pipeline stream.

Screenshots and logs
If applicable, add screenshots and logs to help explain your problem.

403 Client Error: Forbidden for url: https://gitlab.com/api/v4/projects/[redacted]/pipelines?per_page=50&updated_after=2023-01-03T02%3A49%3A24Z

[thomas-gerber]

@cjwooo would it be a good idea to silently ignore streams that produce 403s?

[cjwooo]

I think we should still error in cases like this, so that the connector will still signal to the user that there could be an authn/z issue. If the user determines afterwards that the cause was a feature not being enabled, e.g. CI/CD for a GitLab project, they should explicitly disable the stream.