Bump virtualenv from 20.24.2 to 20.26.6 (#55)

Bumps [virtualenv](https://github.com/pypa/virtualenv) from 20.24.2 to 20.26.6.
- [Release notes](https://github.com/pypa/virtualenv/releases)
- [Changelog](https://github.com/pypa/virtualenv/blob/main/docs/changelog.rst)
- [Commits](pypa/virtualenv@20.24.2...20.26.6)

---
updated-dependencies:
- dependency-name: virtualenv
  dependency-type: direct:development
...

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

requirements-dev.txt

@@ -6,4 +6,4 @@ nodeenv==1.8.0
 platformdirs==3.9.1
 pre-commit==3.3.3
 PyYAML==6.0.1
-virtualenv==20.24.2
+virtualenv==20.26.6