codeintel: Add SoftDeleteExpiredUploads
Created by: efritz
This PR adds the SoftDeleteExpiredUploads
method to the dbstore. This will select all upload records that are both expired and have no uploads referencing it, then soft delete it.
This will soon replace the SoftDeleteOldUploads
method, which cause a lot of issues with high scale (constant contention on the lsif_uploads table).
Prerequisites: