build(deps-dev): bump virtualenv in /samples/client/echo_api/python

Bumps [virtualenv](https://github.com/pypa/virtualenv) from 20.27.1 to 20.36.1.
- [Release notes](https://github.com/pypa/virtualenv/releases)
- [Changelog](https://github.com/pypa/virtualenv/blob/main/docs/changelog.rst)
- [Commits](pypa/virtualenv@20.27.1...20.36.1)

---
updated-dependencies:
- dependency-name: virtualenv
  dependency-version: 20.36.1
  dependency-type: indirect
...

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

Author: dependabot[bot]