Update axum requirement from 0.7 to 0.8

Updates the requirements on [axum](https://github.com/tokio-rs/axum) to permit the latest version.
- [Release notes](https://github.com/tokio-rs/axum/releases)
- [Changelog](https://github.com/tokio-rs/axum/blob/main/CHANGELOG.md)
- [Commits](https://github.com/tokio-rs/axum/commits)

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

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

Cargo.toml

@@ -39,7 +39,7 @@ assimp-sys = { version = "0.3.1", optional = true }
 tempfile = { version = "3.8", optional = true }
 
 [target.'cfg(not(target_family = "wasm"))'.dependencies]
-axum = "0.7"
+axum = "0.8"
 ctrlc = { version = "3", features = ["termination"] }
 tokio = { version = "1", features = ["full"] }
 tower-http = { version = "0.6", features = ["trace"] }