Bump axum-core from 0.2.7 to 0.2.8

Bumps [axum-core](https://github.com/tokio-rs/axum) from 0.2.7 to 0.2.8.
- [Release notes](https://github.com/tokio-rs/axum/releases)
- [Changelog](https://github.com/tokio-rs/axum/blob/main/CHANGELOG.md)
- [Commits](tokio-rs/axum@axum-core-v0.2.7...axum-core-v0.2.8)

---
updated-dependencies:
- dependency-name: axum-core
  dependency-type: indirect
...

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