build(deps): bump pytest-mock from 3.3.1 to 3.5.1

Bumps [pytest-mock](https://github.com/pytest-dev/pytest-mock) from 3.3.1 to 3.5.1.
- [Release notes](https://github.com/pytest-dev/pytest-mock/releases)
- [Changelog](https://github.com/pytest-dev/pytest-mock/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest-mock@v3.3.1...v3.5.1)

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