Update dependency virtualenv to v20.26.6 [SECURITY]

Author: renovate[bot]

requirements.txt

@@ -71,6 +71,6 @@ tomlkit==0.13.0 ; python_version >= "3.10" and python_version < "4.0"
 trove-classifiers==2024.7.2 ; python_version >= "3.10" and python_version < "4.0"
 typing-extensions==4.12.2 ; python_version >= "3.10" and python_version < "3.11"
 urllib3==2.2.2 ; python_version >= "3.10" and python_version < "4.0"
-virtualenv==20.26.3 ; python_version >= "3.10" and python_version < "4.0"
+virtualenv==20.26.6 ; python_version >= "3.10" and python_version < "4.0"
 xattr==1.1.0 ; python_version >= "3.10" and python_version < "4.0" and sys_platform == "darwin"
 zipp==3.19.2 ; python_version >= "3.10" and python_version < "3.12"