add xml plugin to workflow

Author: bbrks

.github/workflows/prettier.yml

@@ -33,6 +33,8 @@ jobs:
       - name: Prettier validation
         uses: creyD/[email protected]
         with:
+          prettier_plugins: |
+            @prettier/plugin-xml
           dry: True
       - name: Find Comment
         if: failure() && github.event_name == 'pull_request'