build(deps): update tower requirement from 0.4 to 0.5

Updates the requirements on [tower](https://github.com/tower-rs/tower) to permit the latest version.
- [Release notes](https://github.com/tower-rs/tower/releases)
- [Commits](tower-rs/tower@tower-0.4.0...tower-0.5.1)

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

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

askama_axum/Cargo.toml

@@ -22,7 +22,7 @@ http = "1.0"
 axum = { version = "0.7", default-features = false }
 http-body-util = "0.1"
 tokio = { version = "1.0", features = ["macros", "rt"] }
-tower = "0.4"
+tower = "0.5"
 
 [features]
 default = ["askama/default"]