Fix formatting: move #[allow(dead_code)] to separate line

Cargo fmt requires attribute macros to be on their own line.
This fixes the CI lint failure.

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Co-Authored-By: Claude <noreply@anthropic.com>

src/parser/gradient.rs

@@ -10,7 +10,8 @@ pub struct ColorStop {
 #[derive(Debug, Clone)]
 pub struct Gradient {
     pub stops: Vec<ColorStop>,
-    #[allow(dead_code)] pub angle: f64,
+    #[allow(dead_code)]
+    pub angle: f64,
 }
 
 impl Gradient {