Bump pip from 23.3 to 25.2 in /utils/google_app_engine (#13663)

Bumps [pip](https://github.com/pypa/pip) from 23.3 to 25.2.
- [Changelog](https://github.com/pypa/pip/blob/main/NEWS.rst)
- [Commits](pypa/pip@23.3...25.2)

---
updated-dependencies:
- dependency-name: pip
  dependency-version: '25.2'
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

utils/google_app_engine/additional_requirements.txt

@@ -1,5 +1,5 @@
 # add these requirements in your app on top of the existing ones
-pip==23.3
+pip==25.2
 Flask==2.3.2
 gunicorn==23.0.0
 werkzeug>=3.0.1 # not directly required, pinned by Snyk to avoid a vulnerability