WebIDL: use FLoat32Array in XRRigidTransform

[gterzian]

Depends on #30990

How to do it:

1. In CodegenRust.py remove XRRigidTransform from the list in todo_switch_float_32.
2. Replace matrix: Heap<*mut JSObject> with HeapFloat32Array.
3. Replace Matrix to return a Float32Array, by using set_data and doing the same as in AudioBuffer::GetChannelData

Any questions, ask here or in https://servo.zulipchat.com/

[gterzian]

part of #30862