Bump riscv-pk from `3ed18cf` to `acbe166`

Bumps [riscv-pk](https://github.com/riscv/riscv-pk) from `3ed18cf` to `acbe166`.
- [Commits](https://github.com/riscv/riscv-pk/compare/3ed18cfbc707c75af83941e8fdf7f68f5a3b4803...acbe166dac9d1db752ee95f61e65ca82bb875afb

)

---
updated-dependencies:
- dependency-name: riscv-pk
  dependency-type: direct:production
...

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