ci(workflow): simplify PR deployment by removing redundant repo/ref lookup (#4266)

# Description of Changes

- Removed the separate step that fetched PR repository and ref
(`get-pr-info`).
- Simplified checkout by directly using `refs/pull/${{
needs.check-comment.outputs.pr_number }}/merge`.
- This reduces workflow complexity and avoids unnecessary API calls
while still supporting forked PRs.

---

## Checklist

### General

- [x] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [x] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [x] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

.github/workflows/PR-Demo-Comment-with-react.yml

@@ -33,8 +33,6 @@ jobs:
       )
     outputs:
       pr_number: ${{ steps.get-pr.outputs.pr_number }}
-      pr_repository: ${{ steps.get-pr-info.outputs.repository }}
-      pr_ref: ${{ steps.get-pr-info.outputs.ref }}
       comment_id: ${{ github.event.comment.id }}
       disable_security: ${{ steps.check-security-flag.outputs.disable_security }}
       enable_pro: ${{ steps.check-pro-flag.outputs.enable_pro }}
@@ -66,29 +64,6 @@ jobs:
             console.log(`PR Number: ${prNumber}`);
             core.setOutput('pr_number', prNumber);
 
-      - name: Get PR repository and ref
-        id: get-pr-info
-        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
-        with:
-          script: |
-            const { owner, repo } = context.repo;
-            const prNumber = context.payload.issue.number;
-
-            const { data: pr } = await github.rest.pulls.get({
-              owner,
-              repo,
-              pull_number: prNumber,
-            });
-
-            // For forks, use the full repository name, for internal PRs use the current repo
-            const repository = pr.head.repo.fork ? pr.head.repo.full_name : `${owner}/${repo}`;
-
-            console.log(`PR Repository: ${repository}`);
-            console.log(`PR Branch: ${pr.head.ref}`);
-
-            core.setOutput('repository', repository);
-            core.setOutput('ref', pr.head.ref);
-
       - name: Check for security/login flag
         id: check-security-flag
         env:
@@ -171,8 +146,7 @@ jobs:
       - name: Checkout PR
         uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
         with:
-          repository: ${{ needs.check-comment.outputs.pr_repository }}
-          ref: ${{ needs.check-comment.outputs.pr_ref }}
+          ref: refs/pull/${{ needs.check-comment.outputs.pr_number }}/merge
           token: ${{ steps.setup-bot.outputs.token }}
 
       - name: Set up JDK