Bump virtualenv from 20.28.0 to 20.28.1

Bumps [virtualenv](https://github.com/pypa/virtualenv) from 20.28.0 to 20.28.1.
- [Release notes](https://github.com/pypa/virtualenv/releases)
- [Changelog](https://github.com/pypa/virtualenv/blob/main/docs/changelog.rst)
- [Commits](pypa/virtualenv@20.28.0...20.28.1)

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

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

development-requirements.txt

@@ -27,5 +27,5 @@ sphinxcontrib-jsmath==1.0.1
 sphinxcontrib-qthelp==2.0.0
 sphinxcontrib-serializinghtml==2.0.0
 twine==6.0.1
-virtualenv==20.28.0
+virtualenv==20.28.1
 wheel==0.45.1