Bump virtualenv from 21.3.0 to 21.3.1

Bumps [virtualenv](https://github.com/pypa/virtualenv) from 21.3.0 to 21.3.1.
- [Release notes](https://github.com/pypa/virtualenv/releases)
- [Changelog](https://github.com/pypa/virtualenv/blob/main/docs/changelog.rst)
- [Commits](pypa/virtualenv@21.3.0...21.3.1)

---
updated-dependencies:
- dependency-name: virtualenv
  dependency-version: 21.3.1
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

pyproject.toml

@@ -45,7 +45,7 @@ development = [
   "pytest==9.0.3; python_version > '3.11'",
   "twine==6.2.0",
   "typing_extensions==4.15.0; python_version < '3.11'",
-  "virtualenv==21.3.0",
+  "virtualenv==21.3.1",
   "wheel==0.47.0",
 ]
 documentation = [