Bump virtualenv from 20.13.0 to 20.13.1

Bumps [virtualenv](https://github.com/pypa/virtualenv) from 20.13.0 to 20.13.1.
- [Release notes](https://github.com/pypa/virtualenv/releases)
- [Changelog](https://github.com/pypa/virtualenv/blob/main/docs/changelog.rst)
- [Commits](pypa/virtualenv@20.13.0...20.13.1)

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

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

Author: dependabot[bot]

requirements-dev.txt

@@ -29,4 +29,4 @@ tomli==2.0.0
 tox==3.24.5
 typing-extensions==4.0.1
 urllib3==1.26.8
-virtualenv==20.13.0
+virtualenv==20.13.1