Bump virtualenv from 20.26.4 to 20.26.6

Bumps [virtualenv](https://github.com/pypa/virtualenv) from 20.26.4 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@20.26.4...20.26.6)

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

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

Author: dependabot[bot]

requirements-test.txt

@@ -107,7 +107,7 @@ typing-extensions==4.12.2
     #   psycopg
 urllib3==2.2.3
     # via requests
-virtualenv==20.26.4
+virtualenv==20.26.6
     # via tox
 wheel==0.44.0
     # via fixattiosync (pyproject.toml)