ci: use npm ci when lockfile exists; fallback to npm install

Author: DavidMenting

.github/workflows/deploy.yml

@@ -28,7 +28,12 @@ jobs:
           cache: 'npm'
 
       - name: Install dependencies
-        run: npm ci
+        run: |
+          if [ -f package-lock.json ]; then
+            npm ci
+          else
+            npm install
+          fi
         
       - name: Build
         run: npm run build
@@ -52,4 +57,4 @@ jobs:
     steps:
       - name: Deploy to GitHub Pages
         id: deployment
-        uses: actions/deploy-pages@v4
+        uses: actions/deploy-pages@v4