Bump virtualenv from 20.17.1 to 20.19.0 in /.github/workflows

Bumps [virtualenv](https://github.com/pypa/virtualenv) from 20.17.1 to 20.19.0.
- [Release notes](https://github.com/pypa/virtualenv/releases)
- [Changelog](https://github.com/pypa/virtualenv/blob/main/docs/changelog.rst)
- [Commits](pypa/virtualenv@20.17.1...20.19.0)

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

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

Author: dependabot[bot]

.github/workflows/constraints.txt

@@ -2,4 +2,4 @@ pip==22.3.1
 nox==2022.11.21
 nox-poetry==1.0.2
 poetry~=1.3.2
-virtualenv==20.17.1
+virtualenv==20.19.0