deps: update jsonwebtoken requirement from 9.3 to 10.2 in /backend

Updates the requirements on [jsonwebtoken](https://github.com/Keats/jsonwebtoken) to permit the latest version.
- [Changelog](https://github.com/Keats/jsonwebtoken/blob/master/CHANGELOG.md)
- [Commits](Keats/jsonwebtoken@v9.3.0...v10.2.0)

---
updated-dependencies:
- dependency-name: jsonwebtoken
  dependency-version: 10.2.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]

backend/Cargo.toml

@@ -20,7 +20,7 @@ tower_governor = "0.8"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 sqlx = { version = "0.8", features = ["runtime-tokio-rustls", "sqlite"] }
-jsonwebtoken = "9.3"
+jsonwebtoken = "10.2"
 bcrypt = "0.17"
 chrono = { version = "0.4", features = ["serde"] }
 dotenv = "0.15"