Revert "Update to Drupal 9"

Revert back so that we can continue to use the Config Installer module.

This reverts commit e5b86c7f39.

tools/ansible/deploy/after-symlink-shared.yml

@@ -1,7 +1,7 @@
 ---
 - name: Install Drupal
   command: |
-    {{ release_drush_path }} site-install -y \
+    {{ release_drush_path }} site-install config_installer -y
     --account-pass=admin123
   args:
     chdir: '{{ release_drupal_path }}'