build(deps): bump virtualenv in /.github/workflows (#213)

Bumps [virtualenv](https://github.com/pypa/virtualenv) from 20.15.1 to 20.16.2.
- [Release notes](https://github.com/pypa/virtualenv/releases)
- [Changelog](https://github.com/pypa/virtualenv/blob/main/docs/changelog.rst)
- [Commits](https://github.com/pypa/virtualenv/compare/20.15.1...20.16.2)

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

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/constraints.txt

@@ -2,5 +2,5 @@ pip==22.2.1
 nox==2022.1.7
 nox-poetry==1.0.1
 poetry==1.1.14
-virtualenv==20.15.1
+virtualenv==20.16.2
 poetry-dynamic-versioning==0.17.1