build(deps-dev): bump hardhat in /tools/hardhat-example

Bumps [hardhat](https://github.com/NomicFoundation/hardhat/tree/HEAD/v-next/hardhat) from 2.26.1 to 3.0.3.
- [Release notes](https://github.com/NomicFoundation/hardhat/releases)
- [Changelog](https://github.com/NomicFoundation/hardhat/blob/main/v-next/hardhat/CHANGELOG.md)
- [Commits](https://github.com/NomicFoundation/hardhat/commits/[email protected]/v-next/hardhat)

---
updated-dependencies:
- dependency-name: hardhat
  dependency-version: 3.0.3
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]