Bump shipmonk/phpstan-rules from 2.7.0 to 2.9.1 (#66)

Bumps [shipmonk/phpstan-rules](https://github.com/shipmonk-rnd/phpstan-rules) from 2.7.0 to 2.9.1.
- [Release notes](https://github.com/shipmonk-rnd/phpstan-rules/releases)
- [Commits](shipmonk-rnd/phpstan-rules@2.7.0...2.9.1)

---
updated-dependencies:
- dependency-name: shipmonk/phpstan-rules
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>