check-migration script failed due to outdated migration path

During the migration test for [1.21.1's host containers](https://github.com/bottlerocket-os/bottlerocket/pull/4153), I notice that the `check-migration` task failed with error
```
Found 4 problem(s) with data store migrations:
- Migration 'aws-admin-container-v0-11-10' does not exist
- Migration 'public-admin-container-v0-11-10' does not exist
- Migration 'aws-control-container-v0-7-14' does not exist
- Migration 'public-control-container-v0-7-14' does not exist
```

By looking at the Twoliter code, it is because it is pointing to an outdated root path for migrations. See https://github.com/bottlerocket-os/twoliter/blob/efd17d998a6b59cb1d26866d155f8c4db3f6bcc2/twoliter/embedded/Makefile.toml#L556

It should be now updated to `sources/settings-migrations/v${version}`.

Start at twoliter/embedded/Makefile.toml near the referenced migration path and compare it with the path reported in the issue. Update the root path to sources/settings-migrations/v${version}, then rerun the check-migration task against the 1.21.1 host-container migration test and confirm the missing-migration errors are gone.

Written by the indexing model from the issue text.