CreateDockerWorkerVersion does not validate the user configuration

The CreateWorkerVersion endpoint validates that the user_configuration matches the expected structure, but CreateDockerWorkerVersion doesn't. Since CreateWorkerVersion is now only used by the frontend when creating a worker version manually, and all workers now rely on CreateDockerWorkerVersion via arkindex workers publish, this means that user configurations are no longer validated for any worker.

This can lead to issues in the frontend's configuration form, as it gets values that it does not expect: ARKINDEX-FRONTEND-BFW