check format in a seperate job

.github/workflows/event-pull_request.yml

@@ -29,13 +29,29 @@ jobs:
         run: sudo .install/install_script.sh
       - name: install python packages
         run: pip3 install -r requirements.txt
-      - name: check format
-        run: make check-format
       - name: unit tests
         run: make unit_test
       - name: flow tests
         run: make flow_test VERBOSE=1
 
+  format:
+    name: format
+    runs-on: ubuntu-24.04
+    needs: check-if-docs-only
+    if: needs.check-if-docs-only.outputs.only-docs-changed == 'false'
+    concurrency:
+      group: ${{ github.workflow }}-${{ github.ref }}
+      cancel-in-progress: true
+    steps:
+      - name: checkout
+        uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.number && format('refs/pull/{0}/merge', github.event.number) || github.head_ref }}
+      - name: install dependencies
+        run: sudo .install/install_script.sh
+      - name: check format
+        run: make check-format
+
   coverage:
     needs: [basic-tests, check-if-docs-only]
     if: ${{ !github.event.pull_request.draft && needs.check-if-docs-only.outputs.only-docs-changed == 'false' }}