Bump dropshot from 53106a8 to 99261d7 (#68)

Bumps [dropshot](https://github.com/oxidecomputer/dropshot) from `53106a8` to `99261d7`.
- [Release notes](https://github.com/oxidecomputer/dropshot/releases)
- [Commits](oxidecomputer/dropshot@53106a8...99261d7)

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

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