Use "node --run" instead of "npm run" (#3764)

This has the advantage that the package manager is no longer involved
after the installation process.

However, previous start commands such as `npm run start` continue to
work. So we don't even have to adapt the documentation.

.github/workflows/spellcheck.yaml

@@ -26,6 +26,6 @@ jobs:
           cache: "npm"
       - name: Install dependencies
         run: |
-          npm run install-mm:dev
+          node --run install-mm:dev
       - name: Run Spellcheck
-        run: npm run test:spelling
+        run: node --run test:spelling