Fix kwarg bug in iree.runtime.load_vm_flatbuffer (#7120)
Fix kwarg bug in iree.runtime.load_vm_flatbuffer (#7120)

Passing `driver` had no effect other than circumventing error checking. 
iree-org/iree,google/iree,iree-org/iree,google/iree,google/iree,google/iree,google/iree,google/iree,iree-org/iree,google/iree,iree-org/iree,iree-org/iree,iree-org/iree,iree-org/iree