Fix wrong return type in set_bit in cuda kernel.

[hzhangxyz]

Description

Fix wrong return type in set_bit in cuda kernel.

Checklist:

• I have read the CONTRIBUTING.md.

[Copilot]

Pull Request Overview

This PR updates the return type of the CUDA kernel function set_bit from bool to void, ensuring that the function correctly reflects its behavior of modifying data in-place without returning a value.

• Changes the signature of set_bit to return void.
• Ensures that the bit-setting operation updates the data correctly without using a return value.

Comments suppressed due to low confidence (1)

qmb/_hamiltonian_cuda.cu:45

• Changing the return type to void clarifies that the set_bit function is used solely for its side-effect. Ensure that any call sites expecting a bool return value are updated accordingly.

__device__ void set_bit(std::uint8_t* data, std::uint8_t index, bool value) {