Bump virtualenv from 20.25.0 to 20.26.6

Bumps [virtualenv](https://github.com/pypa/virtualenv) from 20.25.0 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@20.25.0...20.26.6)

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

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

requirements-dev.txt

@@ -74,7 +74,7 @@ tomlkit==0.12.3 ; python_full_version >= "3.8.1" and python_version < "4.0"
 types-python-dateutil==2.8.19.14 ; python_full_version >= "3.8.1" and python_version < "4.0"
 typing-extensions==4.9.0 ; python_full_version >= "3.8.1" and python_version < "3.11"
 urllib3==2.1.0 ; python_full_version >= "3.8.1" and python_version < "4.0"
-virtualenv==20.25.0 ; python_full_version >= "3.8.1" and python_version < "4.0"
+virtualenv==20.26.6 ; python_full_version >= "3.8.1" and python_version < "4.0"
 wcmatch==8.5 ; python_full_version >= "3.8.1" and python_version < "4.0"
 wrapt==1.16.0 ; python_full_version >= "3.8.1" and python_version < "4.0"
 yamllint==1.33.0 ; python_full_version >= "3.8.1" and python_version < "4.0"