Update validator requirement from 0.17 to 0.18

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

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

Cargo.toml

@@ -29,12 +29,12 @@ multer = "2.0"
 paste = "1.0"
 serde = "1.0"
 thiserror = "1.0"
-validator = "0.17"
+validator = "0.18"
 
 [dev-dependencies]
 futures-executor = "0.3.15"
 gotham = { version = "0.7", features = ["testing"], default-features = false }
 percent-encoding = "2.1"
 pretty_env_logger = "0.5"
 trybuild = "=1.0.89"
-validator = { version = "0.17", features = ["derive"] }
+validator = { version = "0.18", features = ["derive"] }