Bump actix-web from 4.7.0 to 4.8.0 in /rust-backend

Bumps [actix-web](https://github.com/actix/actix-web) from 4.7.0 to 4.8.0.
- [Release notes](https://github.com/actix/actix-web/releases)
- [Changelog](https://github.com/actix/actix-web/blob/master/CHANGES.md)
- [Commits](actix/actix-web@web-v4.7.0...web-v4.8.0)

---
updated-dependencies:
- dependency-name: actix-web
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

rust-backend/Cargo.lock

@@ -6,7 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-actix-web = "4.7.0"
+actix-web = "4.8.0"
 chrono = { version = "0.4.38", features = ["serde"] }
 env_logger = "0.11.3"
 r2d2 = "0.8.10"