refactor: Reorganize GitHub Actions for better reusability (#5949)

## Summary

This PR refactors the GitHub Actions workflow structure to improve
reusability, maintainability, and CI performance.

## Changes

### New Actions
- **setup-comfyui-server**: New composite action that handles ComfyUI
server setup and launch
  - Checks out ComfyUI repository
  - Installs ComfyUI_devtools custom node
  - Sets up Python environment and dependencies
  - Optionally launches the server with configurable parameters

### Refactored Actions
- **setup-frontend**: Simplified to focus only on frontend-specific
tasks
  - Installs pnpm and Node.js
  - Installs dependencies
- Optionally builds the frontend (can be skipped when using cached
builds)
  - No longer handles server setup or checkout

### Workflow Improvements

#### tests-ci.yaml
- Introduced a setup job that builds once and caches the entire
workspace
- Test jobs now restore the cached workspace instead of rebuilding
- Eliminated redundant setup steps in each test shard
- Better separation between setup and test execution phases
- Significant performance improvement through workspace caching

#### Locale Update Workflows
- Updated `update-locales.yaml` to use the new action structure
- Updated `update-locales-for-given-custom-node-repository.yaml` with
proper custom node installation
- Updated `update-node-definitions-locales.yaml` to use new actions
- Removed `working-directory` references where appropriate

#### Other Workflows
- Updated `update-playwright-expectations.yaml` to use new action
structure
- Consistent action usage across all workflows

## Benefits

1. **Better Performance**: Workspace caching eliminates redundant builds
in CI, significantly reducing test execution time
2. **Improved Maintainability**: Clear separation of concerns makes
actions easier to understand and modify
3. **Enhanced Reusability**: Actions can be composed in different ways
for different workflows
4. **DRY Principle**: Eliminated code duplication across workflows
5. **Easier Debugging**: Smaller, focused actions make it easier to
identify and fix issues

## Testing

- [ ] Verify tests-ci workflow runs successfully
- [ ] Verify locale update workflows function correctly
- [ ] Verify playwright expectations update workflow works
- [ ] Confirm cache/restore mechanism works as expected

## Related Issues

This refactoring addresses workflow complexity and reduces CI runtime by
leveraging GitHub Actions caching more effectively.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-5949-refactor-Reorganize-GitHub-Actions-for-better-reusability-2846d73d365081ae8e16f151423b5a88)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Alexander Brown <drjkl@comfy.org>
Co-authored-by: DrJKL <DrJKL0424@gmail.com>

.github/workflows/update-playwright-expectations.yaml

@@ -54,27 +54,27 @@ jobs:
         uses: actions/checkout@v5
         with:
           ref: ${{ steps.get-branch.outputs.branch }}
-      - name: Setup Frontend
-        uses: ./.github/actions/setup-frontend
+      - name: Setup ComfyUI Server
+        uses: ./.github/actions/setup-comfyui-server
+        with:
+          launch_server: true
       - name: Setup Playwright
         uses: ./.github/actions/setup-playwright
       - name: Run Playwright tests and update snapshots
         id: playwright-tests
         run: pnpm exec playwright test --update-snapshots
         continue-on-error: true
-        working-directory: ComfyUI_frontend
       - uses: actions/upload-artifact@v4
         if: always()
         with:
           name: playwright-report
-          path: ComfyUI_frontend/playwright-report/
+          path: ./playwright-report/
           retention-days: 30
       - name: Debugging info
         run: |
           echo "PR: ${{ github.event.issue.number }}"
           echo "Branch: ${{ steps.get-branch.outputs.branch }}"
           git status
-        working-directory: ComfyUI_frontend
       - name: Commit updated expectations
         run: |
           git config --global user.name 'github-actions'
@@ -86,7 +86,6 @@ jobs:
             git commit -m "[automated] Update test expectations"
             git push origin ${{ steps.get-branch.outputs.branch }}
           fi
-        working-directory: ComfyUI_frontend
 
       - name: Add Done Reaction
         uses: peter-evans/create-or-update-comment@e8674b075228eee787fea43ef493e45ece1004c9