Fix new instance of clippy::derivable_impls

The test explicitly avoids deriving `Default` to make it clear that it's
not generated by a macro.

Author: TheJokr

foundations/tests/settings.rs

@@ -128,6 +128,7 @@ enum NoDefaultEnum {
     Variant2,
 }
 
+#[expect(clippy::derivable_impls, reason = "explicit impl for testing")]
 impl Default for NoDefaultEnum {
     fn default() -> Self {
         Self::Variant2