ci: bump pip from 25.1.1 to 25.3 in /.github/workflows

Bumps [pip](https://github.com/pypa/pip) from 25.1.1 to 25.3.
- [Changelog](https://github.com/pypa/pip/blob/main/NEWS.rst)
- [Commits](pypa/pip@25.1.1...25.3)

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

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

Author: dependabot[bot]

.github/workflows/constraints.txt

@@ -1,4 +1,4 @@
-pip==25.1.1
+pip==25.3
 nox==2025.10.16
 nox-poetry==1.2.0
 poetry==1.8.5