ci: use mergify merge queue

.github/workflows/update-dev-flake-lock.yml

@@ -16,3 +16,5 @@ jobs:
         uses: DeterminateSystems/update-flake-lock@v20
         with:
           path-to-flake-dir: ./dev
+          pr-labels: |
+            merge-queue

.github/workflows/update-flake-lock.yml

@@ -14,3 +14,6 @@ jobs:
         uses: cachix/install-nix-action@v23
       - name: Update flake.lock
         uses: DeterminateSystems/update-flake-lock@v20
+        with:
+          pr-labels: |
+            merge-queue

.mergify.yml

@@ -1,8 +1,8 @@
 queue_rules:
   - name: default
     merge_conditions:
-      - check-success=build (aarch64-darwin)
-      - check-success=build (x86_64-linux)
+      - check-success=buildbot/nix-eval
+      - check-success=build
       - check-success=deploy
 defaults:
   actions: