Finalize RemoveInvalidOrganizationUsers background migration

What does this MR do and why?

Finalize RemoveInvalidOrganizationUsers background migration.

This migration did finish in april, see this comment

This MR is part of a few MR's that will replace the use of Loose Foreign Keys for organization_users table

MR	Description
!169382 (merged)	Add Foreign Key for user_id (NOT VALID)
!180028 (merged)	Add Foreign Key for organization_id (NOT VALID)
!185937 (merged)	Delete invalid organization_users records
This MR	Finalize the job
Next	Make the FK's VALID

References

Related to #493506 (closed)

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