Trigger branch indexing and wait until the release tag job is ready

During the release, a tag is created and the corresponding job must be triggered.

In some race condition, the release tag job is not yet created, waiting for the parent job running a new branch indexing either on regular schedule, either on GitHub payload reception.

The API does not allow to wait for the indexing job, use a loop.

The current implementation breaks without triggering the job nor the downstream jobs.