Use parenthetical notation for Fn traits

Always use the `Fn(T) -> R` format when printing closure traits instead of `Fn<(T,), Output = R>`.

Fix #67100:

```
error[E0277]: expected a `Fn()` closure, found `F`
 --> file.rs:6:13
  |
6 |     call_fn(f)
  |     ------- ^ expected an `Fn()` closure, found `F`
  |     |
  |     required by a bound introduced by this call
  |
  = note: wrap the `F` in a closure with no arguments: `|| { /* code */ }`
note: required by a bound in `call_fn`
 --> file.rs:1:15
  |
1 | fn call_fn<F: Fn() -> ()>(f: &F) {
  |               ^^^^^^^^^^ required by this bound in `call_fn`
help: consider further restricting this bound
  |
5 | fn call_any<F: std::any::Any + Fn()>(f: &F) {
  |                              ++++++
```

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -3197,7 +3197,7 @@ define_print_and_forward_display! {
         if let ty::PredicatePolarity::Negative = self.0.polarity {
             p!("!")
         }
-        p!(print(self.0.trait_ref.print_only_trait_path()));
+        p!(print(self.0.trait_ref.print_trait_sugared()));
     }
 
     PrintClosureAsImpl<'tcx> {