iotests: add test for changing the 'drive' property via 'qom-set' Signed-off-by: Fiona Ebner <f.ebner@proxmox.com> Message-ID: <20250605100938.43133-1-f.ebner@proxmox.com> [kwolf: Fixed up pylint warnings flagged by 297] Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>