Sort dashboard personal projects by latest activity

What does this MR do?

Sorts personal projects in the dashboard based on the latest activity.

Are there points in the code the reviewer needs to double check?

none

Why was this MR needed?

It is generally better to list the projects based on the latest activity or update that was done.

Screenshots (if relevant)

before after

Does this MR meet the acceptance criteria?

yes

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Solves Issue #34879 (moved) gitlab-org/gitlab-ce#34879