Bump pytest-testmon from 2.1.4 to 2.2.0 in /flowmachine

Bumps pytest-testmon from 2.1.4 to 2.2.0.

---
updated-dependencies:
- dependency-name: pytest-testmon
  dependency-version: 2.2.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]