Update ui test suite to nightly-2023-11-20

Author: dtolnay

tests/ui/must-use.stderr

@@ -1,14 +1,22 @@
-error: unused return value of `Interface::f` that must be used
+error: unused pinned boxed `Future` trait object that must be used
   --> tests/ui/must-use.rs:18:5
    |
 18 |     Thing.f();
    |     ^^^^^^^^^
    |
+   = note: futures do nothing unless you `.await` or poll them
 note: the lint level is defined here
   --> tests/ui/must-use.rs:1:9
    |
 1  | #![deny(unused_must_use)]
    |         ^^^^^^^^^^^^^^^
+
+error: unused return value of `Interface::f` that must be used
+  --> tests/ui/must-use.rs:18:5
+   |
+18 |     Thing.f();
+   |     ^^^^^^^^^
+   |
 help: use `let _ = ...` to ignore the resulting value
    |
 18 |     let _ = Thing.f();