Remove RISC-V simulator use #9
Description
Right now, we support running via simulator (risc_v_simulator) and via transpiler (riscv_transpiler).
Simulator is a legacy backend, and until recently it was needed for flamegraphs, but now we can generate flamegraphs with transpiler as well.
So we need to completely remove the use of simulator from this project.
The interfaces should be adapted accordingly, where required, so if, e.g., somewhere we pass either simulator or transpiler, we should have no options anymore.