Bump undici and hardhat

Bumps [undici](https://github.com/nodejs/undici) to 5.28.3 and updates ancestor dependency [hardhat](https://github.com/nomiclabs/hardhat). These dependencies need to be updated together.


Updates `undici` from 4.16.0 to 5.28.3
- [Release notes](https://github.com/nodejs/undici/releases)
- [Commits](nodejs/undici@v4.16.0...v5.28.3)

Updates `hardhat` from 2.9.1 to 2.20.1
- [Release notes](https://github.com/nomiclabs/hardhat/releases)
- [Commits](https://github.com/nomiclabs/hardhat/compare/hardhat@2.9.1...hardhat@2.20.1)

---
updated-dependencies:
- dependency-name: undici
  dependency-type: indirect
- dependency-name: hardhat
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>