Registry Database Migrations Should Maintain Support of n-1 Versions of the Container Registry

Context

As part of Deploy to Production Canary as a Seperate Step ... (#1019 - closed), we'll need to occasionally run the production main stage registry deployment on a database with the migrations from the next version applied, so that next version can run on the canary stage during a validation period. We'll need to ensure that apply the next set of migrations will not impact the version of registry running on the main stage, typically the n-1th version of the registry.