Bump virtualenv from 20.16.7 to 20.25.1 in /src

Bumps [virtualenv](https://github.com/pypa/virtualenv) from 20.16.7 to 20.25.1.
- [Release notes](https://github.com/pypa/virtualenv/releases)
- [Changelog](https://github.com/pypa/virtualenv/blob/main/docs/changelog.rst)
- [Commits](pypa/virtualenv@20.16.7...20.25.1)

---
updated-dependencies:
- dependency-name: virtualenv
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

src/requirements.txt

@@ -80,7 +80,7 @@ tomlkit==0.12.3
     # via
     #   -r src/requirements.txt
     #   pylint
-virtualenv==20.16.7
+virtualenv==20.25.1
     # via
     #   -r src/requirements.txt
     #   pre-commit