Use more minimized test.

tests/ui/impl-trait/in-trait/late-bound-in-object-assocty.rs

@@ -1,12 +1,12 @@
 // Test for issue #132429
 //@compile-flags: -Zunstable-options --edition=2024
+//@check-pass
 
-trait ThreeCellFragment {
-    fn ext_cells<'a>(
-        &'a self,
-    ) -> dyn core::future::Future<Output = impl IntoIterator<Item = u32>> + 'a {
-        //~^ ERROR mismatched types
-        //~| ERROR return type cannot have an unboxed trait object
+use std::future::Future;
+
+trait Test {
+    fn foo<'a>(&'a self) -> Box<dyn Future<Output = impl IntoIterator<Item = u32>>> {
+        Box::new(async { [] })
     }
 }