build(deps): bump the backend-dependencies group with 3 updates

Bumps the backend-dependencies group with 3 updates: [async-trait](https://github.com/dtolnay/async-trait), [axum](https://github.com/tokio-rs/axum) and [axum-macros](https://github.com/tokio-rs/axum).


Updates `async-trait` from 0.1.83 to 0.1.84
- [Release notes](https://github.com/dtolnay/async-trait/releases)
- [Commits](dtolnay/async-trait@0.1.83...0.1.84)

Updates `axum` from 0.7.9 to 0.8.1
- [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)

Updates `axum-macros` from 0.4.2 to 0.5.0
- [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-macros-v0.4.2...axum-macros-v0.5.0)

---
updated-dependencies:
- dependency-name: async-trait
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: backend-dependencies
- dependency-name: axum
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: backend-dependencies
- dependency-name: axum-macros
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: backend-dependencies
...

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

Cargo.toml

@@ -12,9 +12,9 @@ authors = ["DaSCH - Swiss National Data and Service Center for the Humanities"]
 
 [dependencies]
 anyhow = "1"
-async-trait = "0.1.83"
-axum = "0.7.9" # web framework
-axum-macros = "0.4.2"
+async-trait = "0.1.84"
+axum = "0.8.1" # web framework
+axum-macros = "0.5.0"
 clap = { version = "4.5.23", features = ["derive"] } # command-line parser
 config = "0.15.4" # Layered configuration with strong support for 12-factor applications
 chrono = { version = "0.4.39", features = ["serde"] }