Move lint to Rust lints

Author: mo8it

dev/Cargo.toml

@@ -207,6 +207,8 @@ panic = "abort"
 unsafe_code = "forbid"
 # You don't need unstable features in Rustlings and shouldn't rely on them while learning Rust.
 unstable_features = "forbid"
+# Dead code warnings can't be avoided in some exercises and might distract while learning.
+dead_code = "allow"
 
 [lints.clippy]
 # You forgot a `todo!()`!
@@ -217,7 +219,5 @@ empty_loop = "forbid"
 infinite_loop = "deny"
 # You shouldn't leak memory while still learning Rust!
 mem_forget = "deny"
-# Dead code warnings can't be avoided in some exercises and might distract while learning.
-dead_code = "allow"
 # Currently, there are no disallowed methods. This line avoids problems when developing Rustlings.
 disallowed_methods = "allow"