Remove manual Default impl for ListLength (unicode-org#4509)

components/list/src/lib.rs

@@ -106,10 +106,11 @@ pub use ListError as Error;
 /// Represents the style of a list. See the
 /// [CLDR spec](https://unicode.org/reports/tr35/tr35-general.html#ListPatterns)
 /// for an explanation of the different styles.
-#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
+#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash, Default)]
 #[non_exhaustive]
 pub enum ListLength {
     /// A typical list
+    #[default]
     Wide,
     /// A shorter list
     Short,
@@ -118,9 +119,3 @@ pub enum ListLength {
     // *Important*: When adding a variant here, make sure the code in
     // ListFormatterPatterns::{start, middle, end, pair} stays panic-free!
 }
-
-impl Default for ListLength {
-    fn default() -> Self {
-        Self::Wide
-    }
-}