Maintain upgrade stop for Omnibus

What does this MR do and why?

With gitlab#420831 (closed) we want to standardize the upgrade stop to a single source of truth. This MR uses the toolbox upgrade path information to update the omnibus upgrade stop on each release.

Previously each upgrade stop was updated manually:

• 15.11 stop: omnibus-gitlab!6833 (merged)
• 16.3 stop: omnibus-gitlab!7110 (merged)
• 16.7 stop: omnibus-gitlab!7245 (merged)

Author Check-list

• Has documentation been updated?