Bump tokio from 1.36.0 to 1.37.0 in /backend

Bumps [tokio](https://github.com/tokio-rs/tokio) from 1.36.0 to 1.37.0.
- [Release notes](https://github.com/tokio-rs/tokio/releases)
- [Commits](tokio-rs/tokio@tokio-1.36.0...tokio-1.37.0)

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

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

backend/Cargo.toml

@@ -9,7 +9,7 @@ edition = "2021"
 chrono = { version = "0.4", features = ["serde"] }
 uuid = { version = "1.8.0", features = ["v4", "serde"] }
 axum = { version = "0.7", features = ["macros"] }
-tokio = { version = "1.36", features = ["full"] }
+tokio = { version = "1.37", features = ["full"] }
 tower = "0.4"
 sqlx = { version = "0.7", features = ["sqlite", "macros", "migrate", "runtime-tokio", "chrono", "uuid"] }
 serde = "1.0"