Draft: Remove deploy-staging CI job

Why is this change being made?

This chance removes the deploy-staging CI job and disables the apply-redirects-staging CI job.

This is being done so we can depreciate https://about.staging.gitlab.com/. We are depreciating staging environment and its deploy jobs because it continues to add extra complexity for the work @cwoolley-gitlab is doing in the CI file related to #8302 (closed).

Author Checklist

• Correct MR template applied (e.g blog post)
• Provided a concise title for the MR
• Added a description to this MR explaining the reasons for the proposed change, per say-why-not-just-what
• Assign this change to the correct DRI
  • If the DRI for the page/s being updated isn’t immediately clear, then assign it to your manager.
  • If your manager does not have merge rights, please ask someone to merge it AFTER it has been approved by your manager in #mr-buddies.
  • If the changes relate to any part of the project other than updates to content and/or data files please make sure to ping @gl-static-site-editor in a comment for a review and merge. For example changes to .gitlab-ci.yml, JavaScript/CSS/Ruby code or the layout files.

For help with failing pipelines reach out in #mr-buddies in Slack

Related #8383 (closed)