build(deps): bump axum from 6efcb75 to 680cdcb

Bumps [axum](https://github.com/tokio-rs/axum) from `6efcb75` to `680cdcb`.
- [Release notes](https://github.com/tokio-rs/axum/releases)
- [Commits](tokio-rs/axum@6efcb75...680cdcb)

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

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