fix(ci): 🛡️mitigate CVE-2025-8869 by pinning pip to patched commit and upgrading dev dependency pins (#4630)

# Description of Changes

**Summary**
- Enforce wheels-only installs for CI/dev workflows where feasible and
pin `pip` to a specific, patched VCS commit as an interim mitigation.
- Replace the explicit `pip==25.2` entry with a VCS-pinned `pip`
reference in `.github/scripts/requirements_dev.in` and the regenerated
`.github/scripts/requirements_dev.txt`.
- Refresh and re-hash multiple development dependency pins in the locked
`requirements_dev.txt` to ensure reproducible installs and reduce
exposure to vulnerable transitive packages.
- Add notes and guidance for maintainers on reverting the VCS pin once
an official pip release contains the fix.

**Why the change was made**
- CVE-2025-8869 allows malicious sdists to include links that escape the
intended extraction directory, enabling arbitrary file overwrite during
`pip install`. CI and developer automation that installs dev
dependencies are at risk if they process attacker-controlled sdists.
- This PR reduces immediate attack surface by preferring wheel
installations where possible and pinning pip to a known patched commit
until an official fixed pip release is available.


---

## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] 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
- [ ] 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.

testing/cucumber/requirements.txt

@@ -8,9 +8,9 @@ behave==1.3.3 \
     --hash=sha256:2b8f4b64ed2ea756a5a2a73e23defc1c4631e9e724c499e46661778453ebaf51 \
     --hash=sha256:89bdb62af8fb9f147ce245736a5de69f025e5edfb66f1fbe16c5007493f842c0
     # via -r testing/cucumber/requirements.in
-certifi==2025.8.3 \
-    --hash=sha256:e564105f78ded564e3ae7c923924435e1daa7463faeab5bb932bc53ffae63407 \
-    --hash=sha256:f6c12493cfb1b06ba2ff328595af9350c65d6644968e5d3a2ffd78699af217a5
+certifi==2025.10.5 \
+    --hash=sha256:0f212c2744a9bb6de0c56639a6f68afe01ecd92d91f14ae897c4fe7bbeeef0de \
+    --hash=sha256:47c09d31ccf2acf0be3f701ea53595ee7e0b8fa08801c6624be771df09ae7b43
     # via requests
 charset-normalizer==3.4.3 \
     --hash=sha256:00237675befef519d9af72169d8604a067d92755e84fe76492fef5441db05b91 \