[Ingest Manager] Concurrency limiting for enrollment does not work as intended

[roncohen]

Kibana version: master

Unfortunately, limiting concurrency for the enroll endpoint does not work as we intended.

Currently, the suspect is our use of request.events.aborted$.toPromise here.

See the discussion here: #70495 (comment)

[elasticmachine]

Pinging @elastic/ingest-management (Team:Ingest Management)

[ph]

cc @ruflin

[roncohen]

Proposed fix: #73898

[roncohen]

#73898 merged, closing this.

[jfsiii]

Added to Ingest Manager in 7.x #73976 & 7.9 #74043