add mergify

.mergify.yml

@@ -0,0 +1,14 @@
+queue_rules:
+  - name: default
+    merge_conditions:
+      - check-success=tests (macos-latest)
+      - check-success=tests (ubuntu-latest)
+    batch_size: 5
+    merge_method: rebase
+pull_request_rules:
+  - name: merge using the merge queue
+    conditions:
+      - base=main
+      - label~=merge-queue|dependencies
+    actions:
+      queue: {}