Bump phpstan/phpstan from 2.1.29 to 2.1.31

Bumps [phpstan/phpstan](https://github.com/phpstan/phpstan-phar-composer-source) from 2.1.29 to 2.1.31.
- [Commits](https://github.com/phpstan/phpstan-phar-composer-source/commits)

---
updated-dependencies:
- dependency-name: phpstan/phpstan
  dependency-version: 2.1.31
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]