chore: use number of people requesting changes rather than the cdk te…

…am (aws#7001)

mergify does not seem to recognize the condition
'changes-requested-reviews-by=@aws/aws-cdk-team'.

Instead switch over to using number of changes requested reviews.

.mergify.yml

@@ -61,7 +61,7 @@ pull_request_rules:
       comment:
         message: Once all the requested changes have been addressed, and the PR is ready for another review, remember to [dismiss the review](https://help.github.com/en/github/collaborating-with-issues-and-pull-requests/dismissing-a-pull-request-review).
     conditions:
-      - changes-requested-reviews-by=@aws/aws-cdk-team
+      - "#changes-requested-reviews-by>=1"
   - name: remove stale reviews
     actions:
       dismiss_reviews: