riscv64 distribution?

Hi @taku910 , you recently reverted a change made by @gounthar adding riscv64 in `.github/workflows/wheel.yml`. I don't see any explanation in the commit message. What is the rationale behind the revert? Can I help adding it back?
Not sure if the reason was related to QEMU, but RISE now provide for free, native riscv64 runners (https://riseproject.dev/2026/03/24/announcing-the-rise-risc-v-runners-free-native-risc-v-ci-on-github/). I can also help you to set this up.

I am working with [RISE](https://riseproject.dev/) to help spread riscv64 adoption in the python ecosystem, and we would love to see sentencepiece distribute riscv64 wheels. FYI, waiting for sentencepiece to distribute it directly, we build test and deploy a riscv64 wheel in a public registry see https://riseproject.gitlab.io/python/wheel_builder/packages/sentencepiece.html.

Start by reading .github/workflows/wheel.yml and the discussion about the reverted riscv64 change. Compare the current workflow with the RISE native riscv64 runner option and the existing public wheel-builder result. Done means the project’s approach to building, testing, and distributing riscv64 wheels is defined and working.

Written by the indexing model from the issue text.