fix composer allow-plugins in CI

Author: mglaman

.github/workflows/php.yml

@@ -113,6 +113,17 @@ jobs:
         with:
           version: ${{ matrix.drupal }}
           path: ~/drupal
+      -   name: Fix allow-plugins (8.9)
+          if: ${{ matrix.drupal == '^8.9' }}
+          run: |
+              cd ~/drupal
+              composer config --no-plugins allow-plugins.drupal/core-composer-scaffold true
+              composer config --no-plugins allow-plugins.drupal/core-project-message true
+      -   name: Fix allow-plugins
+          run: |
+              cd ~/drupal
+              composer config --no-plugins allow-plugins.composer/installers true
+              composer config --no-plugins allow-plugins.dealerdirect/phpcodesniffer-composer-installer true
       - name: "set the version alias for self"
         run: |
           if [ "${{ github.event_name }}" == 'pull_request' ]; then