build(deps): bump third_party/yosys from `4251d37` to `8596c5c` (#2172)

Bumps [third_party/yosys](https://github.com/YosysHQ/yosys) from `4251d37` to `8596c5c`.
- [Release notes](https://github.com/YosysHQ/yosys/releases)
- [Commits](https://github.com/YosysHQ/yosys/compare/4251d37f4fc66108ead53af677739563de4ee7f8...8596c5ce4915d1727d93df45fc58047f08886b41)

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

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

third_party/yosys

diff --git a/third_party/yosys b/third_party/yosys
index 4251d37..8596c5c 160000
--- a/third_party/yosys
+++ b/third_party/yosys
@@ -1 +1 @@
-Subproject commit 4251d37f4fc66108ead53af677739563de4ee7f8
+Subproject commit 8596c5ce4915d1727d93df45fc58047f08886b41