Bump undici and @devvit/public-api

Bumps [undici](https://github.com/nodejs/undici) to 5.28.2 and updates ancestor dependency @devvit/public-api. These dependencies need to be updated together.


Updates `undici` from 5.21.2 to 5.28.2
- [Release notes](https://github.com/nodejs/undici/releases)
- [Commits](nodejs/undici@v5.21.2...v5.28.2)

Updates `@devvit/public-api` from 0.10.3 to 0.10.12

---
updated-dependencies:
- dependency-name: undici
  dependency-type: indirect
- dependency-name: "@devvit/public-api"
  dependency-type: direct:development
...

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