Open "Update supported enterprise versions" PR as draft

Actions will not run checks on PRs opened by Actions, so opening the PR as draft allows us to trigger PR checks by marking the PR as ready for review.

Author: henrymercer

.github/workflows/update-supported-enterprise-server-versions.yml

@@ -40,5 +40,6 @@ jobs:
           body: ""
           author: GitHub <noreply@github.com>
           branch: update-supported-enterprise-server-versions
+          draft: true
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}