ci(mergify): upgrade configuration to current format

Author: mergify[bot]

.github/mergify.yml

@@ -1,29 +1,23 @@
 queue_rules:
   - name: default
-    conditions: []
-
-pull_request_rules:
-  - name: Automatic merge on approval
-    conditions:
+    queue_conditions:
       - and:
           - 'base==master'
           - '#review-threads-unresolved=0'
           - '#changes-requested-reviews-by=0'
           - 'label!=do-not-merge'
           - '#approved-reviews-by>=1'
-    actions:
-      queue:
-        name: default
-        method: squash
+    merge_conditions: []
+    merge_method: squash
 
+pull_request_rules:
   - name: remove outdated reviews for non trusted authors
     conditions:
       - and:
           - base=master
           - author!=@ecopod
     actions:
       dismiss_reviews: {}
-
   - name: Ask to resolve conflict
     conditions:
       - conflict
@@ -68,3 +62,7 @@ pull_request_rules:
       comment:
         message: |
           Congrats! Your token has been merged.  Consider joining our Discord to stay up to date with other builders in the ecosystem. Make sure to drink plenty of water.
+  - name: Automatic merge on approval
+    conditions: []
+    actions:
+      queue: