[HAL/VMVX] Own bytecode executable data (#24307)

VMVX bytecode modules keep pointers into their archive contents for
function metadata, rodata, and teardown. The HAL module may provide
executable bytes from module-origin rodata, but local-task can signal
completion before it releases retained implementation resources. A
command-buffer/executable destructor running after that signal must
therefore not depend on the caller's module backing memory.

Always clone the VMVX executable bytecode during load and let the
bytecode module own that copy. This keeps the cost on the cold
executable prepare path and preserves the
signal-before-resource-destruction queue completion path.