Re-enable format check (the default behavior).

Author: allevato

.github/workflows/pull_request.yml

@@ -12,6 +12,5 @@ jobs:
     name: Soundness
     uses: swiftlang/github-workflows/.github/workflows/soundness.yml@main
     with:
-      format_check_enabled: false
       license_header_check_enabled: false
       license_header_check_project_name: "Swift.org"