[ mergify ] fix condition of 'merge delay passed' label (#8448)

* [ mergify ] fix condition of 'merge delay passed' label

Add the same conditions that we apply for the last stage of PR: 2 approvers and merge-me label. Otherwise, we get a lot of old PRs as well as some current ones getting the label prematurely.

.github/mergify.yml

 pull_request_rules:
 
   # implementing PR delay logic: apply a label after 2 days of inactivity
-  # the label will allow Mergify to merge (see #8442)
+  # the label will allow Mergify to merge (see #8442, #8448)
   - actions:
       label:
         add:
@@ -9,6 +9,8 @@ pull_request_rules:
     name: Wait for 2 days before validating merge
     conditions:
       - updated-at<2 days ago
+      - label=merge me
+      - '#approved-reviews-by>=2'
 
   # rebase+merge strategy
   - actions: