composer: bump phpstan/phpstan from 2.1.38 to 2.1.40

---
updated-dependencies:
- dependency-name: phpstan/phpstan
  dependency-version: 2.1.40
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]