Add npm to CI

Author: mathieucarbou

.github/workflows/build.yml

@@ -62,6 +62,14 @@ jobs:
         with:
           python-version: "3.x"
 
+      - name: Install npm
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20.x'
+
+      - name: Install html-minifier-terser
+        run: npm install -g html-minifier-terser
+
       - name: Build
         run: |
           python -m pip install --upgrade pip