Remove derive(Copy) on ArrayWindows

The derived `T: Copy` constraint is not appropriate for an iterator by
reference, but we generally do not want `Copy` on iterators anyway.

(cherry picked from commit 2bae85ec52)

library/core/src/slice/iter.rs

@@ -2175,7 +2175,7 @@ unsafe impl<T> Sync for ChunksExactMut<'_, T> where T: Sync {}
 ///
 /// [`array_windows`]: slice::array_windows
 /// [slices]: slice
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone)]
 #[stable(feature = "array_windows", since = "1.94.0")]
 #[must_use = "iterators are lazy and do nothing unless consumed"]
 pub struct ArrayWindows<'a, T: 'a, const N: usize> {