Bump virtualenv from 20.23.0 to 20.25.0 in /.github/workflows (#38)

Bumps [virtualenv](https://github.com/pypa/virtualenv) from 20.23.0 to 20.25.0.
- [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/20.23.0...20.25.0)

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

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

.github/workflows/constraints.txt

@@ -2,4 +2,4 @@ pip==24.0
 nox==2023.4.22
 nox-poetry==1.0.3
 poetry==1.7.1
-virtualenv==20.23.0
+virtualenv==20.25.0