message: Update policy to handle prolonged inactive PRs.
diff: @@ -68,6 +68,12 @@ If the author's been unresponsive for more than 14 days, close the PR due to ina
  author to reopen when they have a chance to make the necessary changes. Make sure to thank the
  author for the changes. Also tag the PR with S-inactive-closed.
  +If there has been no meaningful updates after two triage updates, with no meaningful being defined
  +as no commits or no status updates that show progress (i.e. "Soon TM"). The PR should be closed
  +due to prolonged inactivity and ask the author to reopen when they have a chance to make
  +the necessary changes. Make sure to thank the author for the changes. Also tag the PR
  +with S-inactive-closed.
  +
  *TIP*: if an author is on holiday and you know they won't have a chance to come to a PR for a while,
  you can 'bump' the PR by removing and readding the tag (note that removing/readding requires
  clicking off the tag selection dropdown between the two actions).
  