tenant_migration_donor_service_test currently uses the Scanning RSM, and moving to the newer Streamable RSM requires linking in transport_layer_egress_init and version_impl to properly initialize the service layer.

This can be accomplished within the existing build unit for the test, but db_repl_test is quite large, and to reduce unwanted changes to the other unit tests, it may make sense to split tenant_migration_donor_service_test into its own compilation unit.