Improper deletion of schema on service:delete

Hi. I use Apollo Managed Federation (Studio) and I wanted to reset the schema in Studio to a clean slate and I tried doing `service:delete` on one of my service (of the 2 services I had) and while it deleted the implementing service and its associated schema, the other service got automatically removed (makes sense since there is no federation with 1 service)

But, I wanted to delete the schema of the other service too but am not able to do it. While the implementing service got deleted, the schema still exists and I don't see an option in the UI to delete the schema.

While I can delete and create a new graph, thought of sharing this. Thanks.

Start by reproducing `service:delete` in Apollo Managed Federation Studio with two services, then inspect the resulting service and schema state. Done means the deletion behavior is clearly defined and the remaining schema can be removed or the issue is documented as unsupported.

Written by the indexing model from the issue text.