ci: use github package registry token for installation

Author: mxlje

.github/workflows/build.yml

@@ -10,5 +10,8 @@ jobs:
       - uses: actions/setup-node@v2
         with:
           node-version: 16
+          registry-url: https://npm.pkg.github.com
       - run: npm install
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.GPR_TOKEN }}
       - run: npm run build