ci(mergify): upgrade configuration to current format

Author: mergify[bot]

.github/mergify.yml

@@ -1,15 +1,15 @@
 queue_rules:
   - name: dependabot
-    conditions:
+    queue_conditions:
       - status-success=all-checks-passed
+      - base=main
+      - author=dependabot[bot]
+    merge_conditions:
+      - status-success=all-checks-passed
+    merge_method: merge
 
 pull_request_rules:
   - name: dependabot
-    conditions:
-      - status-success=all-checks-passed
-      - base=main
-      - author=dependabot[bot]
+    conditions: []
     actions:
       queue:
-        method: merge
-        name: dependabot