Bump phpdocumentor/reflection-docblock from 5.5.1 to 5.6.0

Bumps [phpdocumentor/reflection-docblock](https://github.com/phpDocumentor/ReflectionDocBlock) from 5.5.1 to 5.6.0.
- [Release notes](https://github.com/phpDocumentor/ReflectionDocBlock/releases)
- [Commits](phpDocumentor/ReflectionDocBlock@5.5.1...5.6.0)

---
updated-dependencies:
- dependency-name: phpdocumentor/reflection-docblock
  dependency-type: indirect
  update-type: version-update:semver-minor
...

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