Ignore experimental plugin releases

[MarkEWaite]

Ignore experimental plugin releases in docs generator

JENKINS-59861 reports that pipeline steps documentation is published on www.jenkins.io for a plugin that is only available from the experimental update center. We should not publish pipeline step documentation for plugins that are not available from the update center.

[vihaanthora]

Is it possible to find an existing example of this anomaly?

The plugin mentioned in the JIRA issue is present as Git Push Plugin now, which is no longer experimental (strangely, clicking the old plugin link still takes us to that page, which should ideally show page not found).

[zbynek]

@MarkEWaite since jenkins-infra/backend-extension-indexer#35 alpha releases should not be considered and https://www.jenkins.io/doc/pipeline/steps/simple-pull-request-job/ only exists because https://issues.jenkins.io/browse/WEBSITE-630 was never implemented and old stuff is never deleted from the website. Maybe this issue can be closed and WEBSITE-630 reopened as GH issue?

[lemeurherve]

FWIW I've also opened this helpdesk issue about deletion on jenkins.io: jenkins-infra/helpdesk#3360

I haven't started it yet but a priori it can be done relatively quickly.

[lemeurherve]

Since jenkins-infra/jenkins.io#6677 these outdated pages return (for now at least) a 403 error, see jenkins-infra/helpdesk#3360 (comment)