fix: remove npm lock file requirement from CI workflow

Switch from npm ci to npm install and remove cache: npm from
setup-node, since no package-lock.json exists in the repo.
This unblocks the GitHub Actions build and the subsequent
GitHub Pages deployment.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: amirhk

.github/workflows/deploy.yml

@@ -26,10 +26,9 @@ jobs:
         uses: actions/setup-node@v4
         with:
           node-version: 20
-          cache: npm
 
       - name: Install dependencies
-        run: npm ci
+        run: npm install
 
       - name: Build
         run: npm run build