Optimize the schema 11.3.0-to-11.4.0 migration notebook

[eecavanna]

By default, the notebook will dump all collections and restore all collections.

The migrator that takes us from schema 11.3.0 to 11.4.0 only manipulates a single collection: workflow_execution_set.

I noticed this when I migrated the Mongo database in the development environment. In an attempt to reduce the amount of downtime involved in the migration, I edited the migration notebook to only dump and restore the one collection that was being manipulated. I used that edited notebook when migrating the Mongo database in the development environment.

This ticket represents the task of storing that notebook in the repo. I want to do this ahead of tomorrow's release.