Bump annotation-indexer from 1.15 to 1.16 (#307)

Bumps [annotation-indexer](https://github.com/jenkinsci/lib-annotation-indexer) from 1.15 to 1.16.
- [Release notes](https://github.com/jenkinsci/lib-annotation-indexer/releases)
- [Commits](jenkinsci/lib-annotation-indexer@annotation-indexer-1.15...annotation-indexer-1.16)

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

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

core/pom.xml

@@ -91,7 +91,7 @@
     <dependency>
       <groupId>org.jenkins-ci</groupId>
       <artifactId>annotation-indexer</artifactId>
-      <version>1.15</version>
+      <version>1.16</version>
       <optional>true</optional>
     </dependency>
     <dependency>