Remove dead elasticsearch indexing code

Merged Dylan Griffith requested to merge remove-dead-elasticsearch-indexing-code into master

What does this MR do?

Remove dead code ElasticBatchProjectIndexerWorker

This worker was first added in !1144 (merged) in %8.17 but all usages were removed in !13437 (merged) in %12.0 . Given that the usages of this worker have been removed for at least 1 major release now we should be safe to remove this worker itself. In fact we could have removed it already in %13.0 .

Remove dead Elasticsearch indexing locking code

The code paths that used to use these locks have been long removed so we can safely remove them. Additionally these are superceded by better de-duplication mechanisms including sidekiq queue de-duplication for ElasticCommitIndexerWorker, redis sorted sets for other indexing jobs and finally we added a lock inside of ElasticCommitIndexerWorker recently to avoid a related problem that these locks didn't even cover anyway !35842 (merged) .

Screenshots

Does this MR meet the acceptance criteria?

Conformity

Availability and Testing

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

  • Label as security and @ mention @gitlab-com/gl-security/appsec
  • The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
  • Security reports checked/validated by a reviewer from the AppSec team

Related to #221178 (closed)