Bump yosys from 0200a76 to 647d61d

Bumps [yosys](https://github.com/YosysHQ/yosys) from `0200a76` to `647d61d`.
- [Release notes](https://github.com/YosysHQ/yosys/releases)
- [Commits](YosysHQ/yosys@0200a76...647d61d)

---
updated-dependencies:
- dependency-name: yosys
  dependency-type: direct:production
...

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