workflow: use npm

.github/workflows/docu.yml

@@ -7,6 +7,10 @@ on:
     # Review gh actions docs if you want to further define triggers, paths, etc
     # https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#on
 
+defaults:
+  run:
+    working-directory: ./docs
+
 jobs:
   build:
     name: Build Docusaurus
@@ -17,13 +21,13 @@ jobs:
           fetch-depth: 0
       - uses: actions/setup-node@v4
         with:
-          node-version: 18
-          cache: yarn
+          node-version: 20
+          cache: npm
 
       - name: Install dependencies
-        run: yarn install --frozen-lockfile
+        run: npm ci
       - name: Build website
-        run: yarn build
+        run: npm run build
 
       - name: Upload Build Artifact
         uses: actions/upload-pages-artifact@v3