[CI] Force commit of ignored Studio build assets

The studio build output dirs are gitignored, so git-auto-commit-action's
dirty check via `git status` always reports a clean tree and skips the
commit (the `-f` add never runs). Add skip_dirty_check so the ignored,
content-hashed build assets are force-added and committed.

This shared workflow is the one resolved for pull_request_target runs
(local reusable workflow resolved from the default branch).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: dpfaffenbauer

.github/workflows/shared-frontend-build.yaml

@@ -99,4 +99,5 @@ jobs:
         with:
           file_pattern: 'src/CoreShop/Bundle/*/Resources/public/studio/*/**'
           add_options: '-f'
+          skip_dirty_check: true
           commit_message: "Build CoreShop Studio bundles [skip ci]"