build(deps-dev): bump pytest from 6.0.1 to 6.1.2 in /src/karmen_backend

Bumps [pytest](https://github.com/pytest-dev/pytest) from 6.0.1 to 6.1.2.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@6.0.1...6.1.2)

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