Add build step in the npm-publish GitHub Workflow

Add missing step that builds the npm package in the GitHub
workflow, before publishing the code to npm.

.github/workflows/npm-publish.yaml

@@ -20,6 +20,7 @@ jobs:
           registry-url: 'https://registry.npmjs.org'
 
       - run: npm ci
+      - run: npm run build
       - run: npm publish --access public
         env:
           NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}