UAT Y24-120 Part-2

(This UAT release has been re-created with a uat- prefix in tag name)

Part-2 of #4133
Branch name is 4133-y24-120-bug-taken-link-error-when-creating-sequencing-batches
develop is merged to the deployment branch.
Includes:

• Database migration to add a unique-together on asset_links ancestor_id and descendant id
• Override AssetLink's create_edge method to handle race conditions