Automate maintenance tasks as much as possible

Automate maintenance tasks as much as possible.

Could do something like create a pipeline with manual or non-manual jobs that would do certain things, then create a MR with the changes.

Possible jobs:

1. Compress images: !7 (merged)
2. Remove unlinked images !6 (merged) with improvements in !8 (merged)
3. Clean up stopped environments: https://gitlab.com/gitlab-org/gitlab-docs/-/blob/0da29f5769d776b3cb06390e611e6a1eb8fa82f0/.gitlab/ci/build-and-deploy.gitlab-ci.yml#L147-161
4. Fix trailing spaces !9 (merged)
5. Fix quotes: https://gitlab.com/gitlab-com/content-sites/internal-handbook/-/blob/main/.vale/gitlab_base/NonStandardQuotes.yml