Allow compiling orchestrator to riscv

[fire]

Description

Allow compiling orchestrator to riscv

Implementation ideas

I did a partial implementation here but got stuck with 4.3-beta2 working.

https://github.com/V-Sekai-fire/godot-orchestrator/tree/riscv-4.3-beta2

[fire]

It's part of my proposal here I will submit to the godot engine organization in the future. https://github.com/V-Sekai/manuals/blob/main/decisions/20240627-gdextension-as-libriscv.md