message: ci: Update mergify to not loop
  According to Mergify support this should prevent the looping we've seen.
diff: @@ -27,12 +27,23 @@ pull_request_rules:
  queue:
  name: default
  method: squash
  + - name: Add merge train label
  + conditions:
  + - "queue-position >= 0"
  + actions:
  comment:
  message: |
  This PR has been added to the merge queue, and will be merged soon.
  label:
  add:
  - on-merge-train
  + - name: Remove merge train label
  + conditions:
  + - "queue-position = -1"
  + actions:
  + label:
  + remove:
  + - on-merge-train
  - name: Handle security critical PRs
  conditions:
  - "label=SR-Risk"
  @@ -96,9 +107,6 @@ pull_request_rules:
  comment:
  message: |
  Merge failed. Please see automated check logs for more details.
  - label:
  - remove:
  - - on-merge-train
  - name: Nag changesets
  conditions:
  - and:
  