scylla_io_setup: Supported GCP VMs with NVMEs get out of box I/O configs
scylla_io_setup: Supported GCP VMs with NVMEs get out of box I/O configs

Iotune isn't run for supported/recommended GCP instances anymore,
we set the I/O properties now based on GCP tables or our
measurements(where applicable).
Not recommended/supported setups will still run iotune.

Fixes #6631

avikivity/scylla,scylladb/scylla,scylladb/scylla,avikivity/scylla,scylladb/scylla,avikivity/scylla,scylladb/scylla