text: Title: Either don't send email notification or only selectively notify about changes to nimbus-desktop-experiments
  Body: Every change to `main-workspace/nimbus-desktop-experiments` is currently notified to each reviewer by email.
  
  These don't seem to carry much value, as they are generated as part of the process of actually releasing an experiment - the reviewer will go and approve them straight away, and they shouldn't need to know that they've approved them.
  
  Whilst reviewers could use email filters to filter these out, I think the fact that we're adding lots of reviewers means we should consider if it is really necessary to send these notifications out in the first place - or maybe, only a subset of reviewers need them.