ci(mergify): upgrade configuration to current format

Author: mergify[bot]

.github/mergify.yml

@@ -1,16 +1,36 @@
----
 defaults:
   actions:
     queue:
       name: default
-      method: rebase
-      update_method: rebase
-
 queue_rules:
-  - name: default
-    conditions:
+  - name: duplicated default from merge after one approval (no design changes)
+    queue_conditions:
+      - base~=^(main)|(release-.+)$
+      - label!=design
+      - "#approved-reviews-by>=1"
+      - "#changes-requested-reviews-by=0"
+      - check-success=test-lint
+      - check-success=test-protoc
+    merge_conditions:
+      - check-success=test-lint
+      - check-success=test-protoc
+    merge_method: rebase
+    update_method: rebase
+  - name: duplicated default from design changes needs approval from at least one
+      core maintainer
+    queue_conditions:
+      - base~=^(main)|(release-.+)$
+      - label=design
+      - "#approved-reviews-by>=2"
+      - "#changes-requested-reviews-by=0"
+      - "approved-reviews-by=@csi-addons/maintainers"
       - check-success=test-lint
       - check-success=test-protoc
+    merge_conditions:
+      - check-success=test-lint
+      - check-success=test-protoc
+    merge_method: rebase
+    update_method: rebase
 
 pull_request_rules:
   - name: remove outdated approvals
@@ -30,10 +50,8 @@ pull_request_rules:
       - check-success=test-lint
       - check-success=test-protoc
     actions:
-      queue: {}
       dismiss_reviews: {}
       delete_head_branch: {}
-
   - name: design changes needs approval from at least one core maintainer
     conditions:
       - base~=^(main)|(release-.+)$
@@ -44,10 +62,8 @@ pull_request_rules:
       - check-success=test-lint
       - check-success=test-protoc
     actions:
-      queue: {}
       dismiss_reviews: {}
       delete_head_branch: {}
-
   - name: label design changes (update the generated Go files)
     conditions:
       - files~=^(lib/go/)
@@ -65,3 +81,8 @@ pull_request_rules:
       request_reviews:
         users_from_teams:
           - "@csi-addons/maintainers"
+  - name: design changes needs approval from at least one core maintainer + merge
+      after one approval (no design changes)
+    conditions: []
+    actions:
+      queue: