build(deps): bump virtualenv in /.github/workflows

Bumps [virtualenv](https://github.com/pypa/virtualenv) from 20.29.1 to 20.31.1.
- [Release notes](https://github.com/pypa/virtualenv/releases)
- [Changelog](https://github.com/pypa/virtualenv/blob/main/docs/changelog.rst)
- [Commits](pypa/virtualenv@20.29.1...20.31.1)

---
updated-dependencies:
- dependency-name: virtualenv
  dependency-version: 20.31.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

.github/workflows/constraints.txt

@@ -2,4 +2,4 @@ pip==24.3.1
 nox==2024.10.9
 nox-poetry==1.1.0
 poetry==1.8.5
-virtualenv==20.29.1
+virtualenv==20.31.1