Use project access tokens for the multi-pipeline triggers

What does this MR do?

This allows:

• The Trigger:qa-test job to use a new environment variable that contain dedicated Project access token instead of the default $GITLAB_BOT_MULTI_PROJECT_PIPELINE_POLLING_TOKEN variable which is a @gitlab-bot's personal access token that is abused a lot.
• The Trigger:*e-package jobs to use a new environment variable that contain dedicated Project access token instead of the default $GITLAB_BOT_MULTI_PROJECT_PIPELINE_POLLING_TOKEN variable which is a @gitlab-bot's personal access token that is abused a lot.
• The Trigger:RAT job to use a new environment variable that contain dedicated Project access token instead of the default $GITLAB_BOT_MULTI_PROJECT_PIPELINE_POLLING_TOKEN variable which is a @gitlab-bot's personal access token that is abused a lot.
• The RAT-* jobs to use a new environment variable that contain dedicated Project access token instead of the default $GITLAB_BOT_MULTI_PROJECT_PIPELINE_POLLING_TOKEN variable which is a @gitlab-bot's personal access token that is abused a lot.

A similar change is made in the gitlab-org/gitlab project at gitlab!66548 (merged), and in the gitlab-org/gitlab-qa project at gitlab-qa!730 (merged).

The following new project access tokens have been created:

• "Multi-pipeline (from 'gitlab-org/omnibus-gitlab' 'Trigger:*e-package' job)" at https://gitlab.com/gitlab-org/build/omnibus-gitlab-mirror/-/settings/access_tokens
  • Set as masked variable OMNIBUS_GITLAB_MIRROR_PROJECT_ACCESS_TOKEN at https://gitlab.com/gitlab-org/omnibus-gitlab/-/settings/ci_cd
• "Multi-pipeline (from 'gitlab-org/build/omnibus-gitlab-mirror' 'Trigger:qa-test' job)" at https://gitlab.com/gitlab-org/gitlab-qa-mirror/-/settings/access_tokens
  • Set as masked variable GITLAB_QA_MIRROR_PROJECT_ACCESS_TOKEN at https://gitlab.com/gitlab-org/build/omnibus-gitlab-mirror/-/settings/ci_cd
• "Multi-pipeline (from 'gitlab-org/omnibus-gitlab' 'Trigger:RAT' job)" at https://gitlab.com/gitlab-org/distribution/reference-architecture-tester/-/settings/access_tokens
  • Set as masked variable RAT_PROJECT_ACCESS_TOKEN at https://gitlab.com/gitlab-org/omnibus-gitlab/-/settings/ci_cd
• "Multi-pipeline (from 'dev/gitlab/omnibus-gitlab' 'RAT-*' jobs)" at https://gitlab.com/gitlab-org/distribution/reference-architecture-tester/-/settings/access_tokens
  • Set as masked variable RAT_PROJECT_ACCESS_TOKEN at https://dev.gitlab.org/gitlab/omnibus-gitlab/-/settings/ci_cd

Related issues

• https://gitlab.com/gitlab-org/quality/team-tasks/-/issues/943.

Check-list

Pre-merge

• Trigger:ce-package and Trigger:ee-package still triggers a downstream pipeline
  • Comment is successfully posted by the new OMNIBUS_GITLAB_MIRROR_PROJECT_ACCESS_TOKEN from https://gitlab.com/gitlab-org/build/omnibus-gitlab-mirror (Ghost user is a previously revoked token)
• Trigger:qa-test still triggers a downstream pipeline
  • Comment is successfully posted by the new GITLAB_QA_MIRROR_PROJECT_ACCESS_TOKEN from https://gitlab.com/gitlab-org/gitlab-qa-mirror, see gitlab!66548 (merged)

Post-merge

• Consider communicating these changes to the broader team following the communication guideline for pipeline changes