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/syntax/src/tests.rs

@@ -108,7 +108,7 @@ fn self_hosting_parsing() {
             .into_iter()
             .map(|(path, err)| format!("{}: {:?}\n", path.display(), err[0]))
             .collect::<String>();
-        panic!("Parsing errors:\n{}\n", errors);
+        panic!("Parsing errors:\n{errors}\n");
     }
 }
 
@@ -181,6 +181,6 @@ fn rust_files_in_dir(dir: &Path) -> Vec<PathBuf> {
 /// so this should always be correct.
 fn read_text(path: &Path) -> String {
     fs::read_to_string(path)
-        .unwrap_or_else(|_| panic!("File at {:?} should be valid", path))
+        .unwrap_or_else(|_| panic!("File at {path:?} should be valid"))
         .replace("\r\n", "\n")
 }