Bump chiseltest from `3a5c858` to `cb9b2c4` (#307)

Bumps [chiseltest](https://github.com/ucb-bar/chisel-testers2) from `3a5c858` to `cb9b2c4`.
- [Release notes](https://github.com/ucb-bar/chisel-testers2/releases)
- [Commits](https://github.com/ucb-bar/chisel-testers2/compare/3a5c8584a31963e2e49f00b54ff3e61f89a2b233...cb9b2c48bc5646285f33f66ba2a2826700cf54db

)

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

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