Run code style checks in workflow only once (#3648)

It's enough if the code style checks are successful once, it's not
necessary to run them with every node version.

Also, if there is an error, we can see more quickly whether it is a code
style or a test-runner issue.

.github/workflows/automated-tests.yaml

@@ -13,6 +13,26 @@ permissions:
   contents: read
 
 jobs:
+  code-style-check:
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    steps:
+      - name: "Checkout code"
+        uses: actions/checkout@v4
+      - name: "Use Node.js"
+        uses: actions/setup-node@v4
+        with:
+          node-version: 23
+          cache: "npm"
+      - name: "Install dependencies"
+        run: |
+          npm run install-mm:dev
+      - name: "Run linter tests"
+        run: |
+          npm run test:prettier
+          npm run test:js
+          npm run test:css
+          npm run test:markdown
   test:
     runs-on: ubuntu-latest
     timeout-minutes: 30
@@ -36,8 +56,4 @@ jobs:
           Xvfb :99 -screen 0 1024x768x16 &
           export DISPLAY=:99
           touch css/custom.css
-          npm run test:prettier
-          npm run test:js
-          npm run test:css
-          npm run test:markdown
           npm run test