ci(mergify): upgrade configuration to current format

.mergify.yml

@@ -1,29 +1,30 @@
 queue_rules:
-  - name: default
-    conditions:
+  - name: duplicated default from automatic merge for Dependabot pull requests on
+      master
+    queue_conditions:
+      - base=master
+      - "#approved-reviews-by>=1"
+      - label=ready-to-merge
+      - status-success=run_build_pipeline
+      - author=dependabot[bot]
       - status-success=run_build_pipeline
       - base=master
-
-
-pull_request_rules:
-  - name: Automatic merge for approved PRs labelled as ready
-    conditions:
+    merge_conditions: []
+    merge_method: merge
+  - name: default
+    queue_conditions:
       - base=master
       - "#approved-reviews-by>=1"
       - label=ready-to-merge
       - status-success=run_build_pipeline
-    actions:
-      queue:
-        name: default
-        method: merge
-
-  - name: automatic merge for Dependabot pull requests on master
-    conditions:
-      - author=dependabot[bot]
+    merge_conditions:
       - status-success=run_build_pipeline
       - base=master
+    merge_method: merge
+
+pull_request_rules:
+  - name: Automatic merge for approved PRs labelled as ready + automatic merge for
+      Dependabot pull requests on master
+    conditions: []
     actions:
       queue:
-        name: default
-        method: merge
-