Bump the workflows-dependencies group

Bumps the workflows-dependencies group in /.github/workflows with 2 updates: [pip](https://github.com/pypa/pip) and [poetry](https://github.com/python-poetry/poetry).


Updates `pip` from 25.3 to 26.0
- [Changelog](https://github.com/pypa/pip/blob/main/NEWS.rst)
- [Commits](pypa/pip@25.3...26.0)

Updates `poetry` from 2.2.1 to 2.3.1
- [Release notes](https://github.com/python-poetry/poetry/releases)
- [Changelog](https://github.com/python-poetry/poetry/blob/main/CHANGELOG.md)
- [Commits](python-poetry/poetry@2.2.1...2.3.1)

---
updated-dependencies:
- dependency-name: pip
  dependency-version: '26.0'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: workflows-dependencies
- dependency-name: poetry
  dependency-version: 2.3.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: workflows-dependencies
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/constraints.txt

@@ -1,4 +1,4 @@
 nox==2025.11.12
-pip==25.3
+pip==26.0
 nox-poetry==1.2.0
-poetry==2.2.1
+poetry==2.3.1