Bump rector/rector from 0.15.21 to 0.15.23

Bumps [rector/rector](https://github.com/rectorphp/rector) from 0.15.21 to 0.15.23.
- [Release notes](https://github.com/rectorphp/rector/releases)
- [Commits](rectorphp/rector@0.15.21...0.15.23)

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

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Author: dependabot[bot]