Add build-packages step to demo job in integration tests

Author: OskarStark

.github/workflows/integration-tests.yaml

@@ -95,6 +95,9 @@ jobs:
             - name: Install root dependencies
               uses: ramsey/composer-install@v3
 
+            - name: Build root packages
+              run: php .github/build-packages.php
+
             - name: Install demo dependencies
               uses: ramsey/composer-install@v3
               with: