all: address clippy lints

src/rect/region.rs

@@ -234,18 +234,13 @@ where
     }
 }
 
-#[derive(Copy, Clone, Eq, PartialEq, Debug)]
+#[derive(Copy, Clone, Eq, PartialEq, Debug, Default)]
 enum BuilderOp {
+    #[default]
     Add,
     Sub,
 }
 
-impl Default for BuilderOp {
-    fn default() -> Self {
-        Self::Add
-    }
-}
-
 #[derive(Debug)]
 pub struct RegionBuilder {
     base: Rc<Region>,