ci(mergify): upgrade configuration to current format (#191)

Co-authored-by: Mergify <37929162+mergify[bot]@users.noreply.github.com>

.mergify.yml

@@ -1,22 +1,21 @@
 queue_rules:
   - name: default
-    conditions:
-    - check-success=test (py310)
-    - check-success=test (pep8)
-
-pull_request_rules:
-  - name: automatic merge
-    actions:
-      queue:
-        method: squash
-        name: default
-    conditions:
+    queue_conditions:
       - label!=work-in-progress
       - "#approved-reviews-by>=1"
       - check-success=test (py310)
       - check-success=test (pep8)
+    merge_conditions:
+      - check-success=test (py310)
+      - check-success=test (pep8)
+    merge_method: squash
 
+pull_request_rules:
   - name: dismiss reviews
     actions:
       dismiss_reviews: {}
     conditions: []
+  - name: refactored queue action rule
+    conditions: []
+    actions:
+      queue: