build(deps): bump third_party/yosys from 956c4e4 to 611f71c (f4pg…

…a#2092)

Bumps [third_party/yosys](https://github.com/YosysHQ/yosys) from `956c4e4` to `611f71c`.
- [Release notes](https://github.com/YosysHQ/yosys/releases)
- [Commits](YosysHQ/yosys@956c4e4...611f71c)

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

Signed-off-by: dependabot[bot] <support@github.com>

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>