Backfill embeddings for work items
Description
Backfill embeddings for work items on gitlab.com: Work items updated within the last year from the gitlab-org/gitlab project.
The migration only runs on gitlab.com and is skipped for other instances.
This is based on !154940 (merged).
Migration running
Running the migration locally and it works well
When there are no projects with the flag enabled
Sets space required to 0B, marks as completed.
When there is a project with the flag enabled and it spans over two batches: 40 docs, batch size 30
First run calculates size correctly, enqueues 30 docs
Second run enqueues 10 docs
Third run marks as completed
If the space required is not enough
It halts the migration
Runtime calculation
Related to #479777 (closed).
Edited by Arturo Herrero