build(deps): bump third_party/tools/icarus from 9a0ce04 to 7c25e85

Bumps [third_party/tools/icarus](https://github.com/steveicarus/iverilog) from `9a0ce04` to `7c25e85`.
- [Release notes](https://github.com/steveicarus/iverilog/releases)
- [Commits](steveicarus/iverilog@9a0ce04...7c25e85)

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

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