Bump pip from 23.3 to 25.3 in /docker

Bumps [pip](https://github.com/pypa/pip) from 23.3 to 25.3.
- [Changelog](https://github.com/pypa/pip/blob/main/NEWS.rst)
- [Commits](pypa/pip@23.3...25.3)

---
updated-dependencies:
- dependency-name: pip
  dependency-version: '25.3'
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

docker/requirements.txt

@@ -21,5 +21,5 @@ virtualenv==20.26.6
 wheel==0.38.4
 
 # The following packages are considered to be unsafe in a requirements file:
-pip==23.3
+pip==25.3
 setuptools==78.1.1