ci(mergify): upgrade configuration to current format

Author: mergify[bot]

.github/mergify.yml

@@ -1,3 +1,4 @@
+
 pull_request_rules:
   - name: self-assign PRs
     conditions:
@@ -9,18 +10,18 @@ pull_request_rules:
         add_users:
           - "{{ author }}"
   - name: automatic merge when not WIP, CI passes, and at least 1 approving review
-    conditions:
+    conditions: []
+    actions:
+      queue:
+queue_rules:
+  - name: default
+    queue_conditions:
       - "#approved-reviews-by>=1"
       - check-success=gitguardian
       - check-success=scidev
       - base=main
       - label!=work-in-progress
-    actions:
-      queue:
-        method: squash
-        name: default
-queue_rules:
-  - name: default
-    conditions:
+    merge_conditions:
       - check-success=gitguardian
       - check-success=scidev
+    merge_method: squash