Check for missing projects in project_security_settings table

This check compares the list of projects in the projects table to the list of project_id's in the project_security_settings table. Unless the two are identical this check will trigger the alert.

Example of trigger message:

{ "ref_url": "https://gitlab.com/gitlab-org/gitlab/-/issues/571158", "title": "missing security settings", "host": "interview-instance.env-57c7bd43.gcp.gitlabsandbox.net", "workaround_url": "https://support.gitlab.com/hc/en-us/articles/22575474919324-500-Error-when-accessing-Pipeline-after-upgrading-to-GitLab-18-4-1", "version_started": "13.2.0", "version_fixed": null, "message": "one or more projects needs security settings, please see https://support.gitlab.com/hc/en-us/articles/22575474919324-500-Error-when-accessing-Pipeline-after-upgrading-to-GitLab-18-4-1" }

This check does not have a "fixed in" version because the underlying issue is a bit more generic than the particular issue that caused problems in GitLab 18.4. In that case a new pipeline check looked for a project security setting with the assumption that it already existed, and failed with a 500 error in the event no security setting entry existed for that project. While the fix for #571158 was backported to GitLab 18.4.2, this check will find the more generic case (of a missing project security setting) that could affect a myriad of code additions in the future.

Fixes #152