Bump annotation-indexer from 1.14 to 1.15 (#5639)

Bumps [annotation-indexer](https://github.com/jenkinsci/lib-annotation-indexer) from 1.14 to 1.15.
- [Release notes](https://github.com/jenkinsci/lib-annotation-indexer/releases)
- [Commits](https://github.com/jenkinsci/lib-annotation-indexer/compare/annotation-indexer-1.14...annotation-indexer-1.15

)

---
updated-dependencies:
- dependency-name: org.jenkins-ci:annotation-indexer
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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