Large # of TAGs or REFs in a GIT repo causes slowdowns and/or timeouts in the UI. (BB-14688)

Having a large # of TAGs or repo REFs in a git repo (3k or more (estimate)) causes slowdowns, and/or timeouts when taking actions in the UI.
For pull requests is causes a decline of a PR, loading a PR, loading change sets within a pr, etc.

Confirmed this with a git repo which has 11k tags. Takes about 10-15 attempts to to decline any PR for this repo for a successful attempt. All other attempts gave a sentry/500 error.