Bump virtualenv from 20.30.0 to 20.31.1

Bumps [virtualenv](https://github.com/pypa/virtualenv) from 20.30.0 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@20.30.0...20.31.1)

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

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

Author: dependabot[bot]

development-requirements.txt

@@ -29,5 +29,5 @@ sphinxcontrib-jsmath==1.0.1
 sphinxcontrib-qthelp==2.0.0
 sphinxcontrib-serializinghtml==2.0.0
 twine==6.1.0
-virtualenv==20.30.0
+virtualenv==20.31.1
 wheel==0.46.1