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

Bumps [virtualenv](https://github.com/pypa/virtualenv) from 20.27.1 to 20.29.3.
- [Release notes](https://github.com/pypa/virtualenv/releases)
- [Changelog](https://github.com/pypa/virtualenv/blob/main/docs/changelog.rst)
- [Commits](pypa/virtualenv@20.27.1...20.29.3)

---
updated-dependencies:
- dependency-name: virtualenv
  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==25.0.1
 pipx==1.4.3,!=1.5,!=1.6.0
 nox==2025.2.9
 nox-poetry==1.1.0
-virtualenv==20.27.1
+virtualenv==20.29.3