Bump phpstan/phpstan-strict-rules from 1.5.3 to 1.5.5

Bumps [phpstan/phpstan-strict-rules](https://github.com/phpstan/phpstan-strict-rules) from 1.5.3 to 1.5.5.
- [Release notes](https://github.com/phpstan/phpstan-strict-rules/releases)
- [Commits](phpstan/phpstan-strict-rules@1.5.3...1.5.5)

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

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