Bump firrtl from `e5eb206` to `af5d544` (#197)

Bumps [firrtl](https://github.com/freechipsproject/firrtl) from `e5eb206` to `af5d544`.
- [Release notes](https://github.com/freechipsproject/firrtl/releases)
- [Commits](https://github.com/freechipsproject/firrtl/compare/e5eb20686baf33728e1d46ea760885474df157db...af5d544a9ca87b00989e4bf7523cd0310238900a

)

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

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