build(deps): bump third_party/yosys from 7d30f71 to 6f1ca68

Bumps [third_party/yosys](https://github.com/YosysHQ/yosys) from `7d30f71` to `6f1ca68`.
- [Release notes](https://github.com/YosysHQ/yosys/releases)
- [Commits](YosysHQ/yosys@7d30f71...6f1ca68)

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

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