Inline all format arguments where possible

This makes code more readale and concise,
moving all format arguments like `format!("{}", foo)`
into the more compact `format!("{foo}")` form.

The change was automatically created with, so there are far less change
of an accidental typo.

```
cargo clippy --fix -- -A clippy::all -W clippy::uninlined_format_args
```

crates/mbe/src/syntax_bridge.rs

@@ -237,7 +237,7 @@ fn convert_tokens<C: TokenConverter>(conv: &mut C) -> tt::Subtree {
             let char = match token.to_char(conv) {
                 Some(c) => c,
                 None => {
-                    panic!("Token from lexer must be single char: token = {:#?}", token);
+                    panic!("Token from lexer must be single char: token = {token:#?}");
                 }
             };
             tt::Leaf::from(tt::Punct { char, spacing, id: conv.id_alloc().alloc(range, synth_id) })