Remove unannotated method in extern spec

Author: nilehmann

flux_support/src/extern_specs/range.rs

@@ -36,11 +36,6 @@ trait RangeBounds<T> {
 
     #[flux_rs::sig(fn(&Self) -> Bound<&T>)]
     fn end_bound(&self) -> Bound<&T>;
-
-    fn contains<U>(&self, item: &U) -> bool
-    where
-        T: PartialOrd<U>,
-        U: ?Sized + PartialOrd<T>;
     // {
     //     (match self.start_bound() {
     //         Included(start) => start <= item,