Update annotation-indexer from 1.7 to 1.11 (#2329)

Diff: https://github.com/jenkinsci/lib-annotation-indexer/compare/e90dade9a07b04b64ac1b08d539d30ad69ddf7a8...2eec43c72b3cd040d2057e6bbbf639f5e030453e

Major changes:
* 1.11 - [JENKINS-32978] support latest source version to avoid compile time warnings with JDK7
* 1.10 - Get ready for JDK 9
* 1.10 - Be tolerant against line separators on different operating systems
* 1.9 - Support of third-party annotations
* 1.8 - Annotation processor can be intercepted