Rollup merge of #92412 - dtolnay:tryspace, r=Mark-Simulacrum

Rollup merge of #92412 - dtolnay:tryspace, r=Mark-Simulacrum

Fix double space in pretty printed TryBlock

Follow-up to #92238 fixing one of the FIXMEs.

```rust
macro_rules! repro {
    ($expr:expr) => {
        stringify!($expr)
    };
}

fn main() {
    println!("{}", repro!(try {}));
}
```

Before:&ensp;<code>try&nbsp;&nbsp;{}</code>
After:&ensp;<code>try&nbsp;{}</code>

The `head` helper already appends a space:

https://github.com/rust-lang/rust/blob/2b67c30bfece00357d5fc09d99b49f21066f04ba/compiler/rustc_ast_pretty/src/pprust/state.rs#L654-L664

so doing `head` followed by `space` resulted in a double space:

https://github.com/rust-lang/rust/blob/2b67c30bfece00357d5fc09d99b49f21066f04ba/compiler/rustc_ast_pretty/src/pprust/state.rs#L2241-L2242