build(deps-dev): bump phpstan/phpstan from 1.11.0 to 1.11.8

Bumps [phpstan/phpstan](https://github.com/phpstan/phpstan) from 1.11.0 to 1.11.8.
- [Release notes](https://github.com/phpstan/phpstan/releases)
- [Changelog](https://github.com/phpstan/phpstan/blob/1.12.x/CHANGELOG.md)
- [Commits](phpstan/phpstan@1.11.0...1.11.8)

---
updated-dependencies:
- dependency-name: phpstan/phpstan
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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