Bump the cargo group in /backend with 5 updates

Bumps the cargo group in /backend with 5 updates:

| Package | From | To |
| --- | --- | --- |
| [tokio](https://github.com/tokio-rs/tokio) | `1.39.2` | `1.39.3` |
| [tower](https://github.com/tower-rs/tower) | `0.4.13` | `0.5.0` |
| [serde](https://github.com/serde-rs/serde) | `1.0.206` | `1.0.208` |
| [serde_json](https://github.com/serde-rs/json) | `1.0.124` | `1.0.125` |
| [clap](https://github.com/clap-rs/clap) | `4.5.15` | `4.5.16` |


Updates `tokio` from 1.39.2 to 1.39.3
- [Release notes](https://github.com/tokio-rs/tokio/releases)
- [Commits](tokio-rs/tokio@tokio-1.39.2...tokio-1.39.3)

Updates `tower` from 0.4.13 to 0.5.0
- [Release notes](https://github.com/tower-rs/tower/releases)
- [Commits](tower-rs/tower@tower-0.4.13...tower-0.5.0)

Updates `serde` from 1.0.206 to 1.0.208
- [Release notes](https://github.com/serde-rs/serde/releases)
- [Commits](serde-rs/serde@v1.0.206...v1.0.208)

Updates `serde_json` from 1.0.124 to 1.0.125
- [Release notes](https://github.com/serde-rs/json/releases)
- [Commits](serde-rs/json@v1.0.124...1.0.125)

Updates `clap` from 4.5.15 to 4.5.16
- [Release notes](https://github.com/clap-rs/clap/releases)
- [Changelog](https://github.com/clap-rs/clap/blob/master/CHANGELOG.md)
- [Commits](clap-rs/clap@clap_complete-v4.5.15...clap_complete-v4.5.16)

---
updated-dependencies:
- dependency-name: tokio
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: cargo
- dependency-name: tower
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: cargo
- dependency-name: serde
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: cargo
- dependency-name: serde_json
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: cargo
- dependency-name: clap
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: cargo
...

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

backend/Cargo.toml

@@ -20,7 +20,7 @@ required-features = ["openapi"]
 axum = { version = "0.7", features = ["macros"] }
 hyper = { version = "1", features = ["full"] }
 tokio = { version = "1", features = ["full"] }
-tower = "0.4"
+tower = "0.5"
 tower-http = { version = "0.5.0", features = ["fs"] }
 utoipa = { version = "4.2", features = ["axum_extras"] }
 utoipa-swagger-ui = { version = "7.1.0", features = ["axum"], optional = true }