Update feature categories to 2024-08-12

What does this MR do and why?

Resolves gitlab-com/gl-infra/scalability#3695 (closed)

Sorry for the big merge request. Unfortunately, the changes contained here cannot be split into multiple MRs. On the good side, it is mostly feature category renames which should be trivial to review.

• The removal of the five_minute_production_app category is being taken care of separately #478491.
• The custom_models category is now a stage group. The former custom_models category is being renamed to self-hosted_models.
• The remote_development category is now workspaces

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