Bump dropshot from 164f2ed to cf285b1 (#653)

Bumps [dropshot](https://github.com/oxidecomputer/dropshot) from `164f2ed` to `cf285b1`.
- [Commits](oxidecomputer/dropshot@164f2ed...cf285b1)

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

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