chore(deps): bump ext/riscv-isa-manual from 5202d9c to 50b4d5d

Bumps [ext/riscv-isa-manual](https://github.com/riscv/riscv-isa-manual) from `5202d9c` to `50b4d5d`.
- [Release notes](https://github.com/riscv/riscv-isa-manual/releases)
- [Commits](riscv/riscv-isa-manual@5202d9c...50b4d5d)

---
updated-dependencies:
- dependency-name: ext/riscv-isa-manual
  dependency-version: 50b4d5d56e5b3bbb23cbaf310f792523a15d58f5
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]