Fix tests after beta backport

Author: Mark-Simulacrum

src/test/ui/type-alias-impl-trait/issue-98604.stderr

@@ -11,7 +11,7 @@ LL | async fn test() {}
    |                 ^ checked the `Output` of this `async fn`, found opaque type
    = note:   expected struct `Pin<Box<(dyn Future<Output = ()> + 'static)>>`
            found opaque type `impl Future<Output = ()>`
-   = note: required for the cast from `fn() -> impl Future<Output = ()> {test}` to the object type `dyn Fn() -> Pin<Box<(dyn Future<Output = ()> + 'static)>>`
+   = note: required for the cast to the object type `dyn Fn() -> Pin<Box<(dyn Future<Output = ()> + 'static)>>`
 
 error: aborting due to previous error
 

src/test/ui/type-alias-impl-trait/issue-98608.stderr

@@ -9,7 +9,7 @@ LL |     let b: Box<dyn Fn() -> Box<u8>> = Box::new(hi);
    |
    = note:   expected struct `Box<u8>`
            found opaque type `impl Sized`
-   = note: required for the cast from `fn() -> impl Sized {hi}` to the object type `dyn Fn() -> Box<u8>`
+   = note: required for the cast to the object type `dyn Fn() -> Box<u8>`
 
 error: aborting due to previous error