Use variable names directly in the format strings (#7906)

# Description

Lint: `clippy::uninlined_format_args`

More readable in most situations.
(May be slightly confusing for modifier format strings
https://doc.rust-lang.org/std/fmt/index.html#formatting-parameters)

Alternative to #7865

# User-Facing Changes

None intended

# Tests + Formatting

(Ran `cargo +stable clippy --fix --workspace -- -A clippy::all -D
clippy::uninlined_format_args` to achieve this. Depends on Rust `1.67`)

crates/nu-protocol/src/ast/cell_path.rs

@@ -34,7 +34,7 @@ impl CellPath {
             }
             match elem {
                 PathMember::Int { val, .. } => {
-                    let _ = write!(output, "{}", val);
+                    let _ = write!(output, "{val}");
                 }
                 PathMember::String { val, .. } => output.push_str(val),
             }