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_plugin_gstat/src/gstat.rs

@@ -385,7 +385,7 @@ impl Stats {
                         if let Ok(commit) = head.peel_to_commit() {
                             let mut id = String::new();
                             for byte in &commit.id().as_bytes()[..4] {
-                                write!(&mut id, "{:x}", byte).unwrap();
+                                write!(&mut id, "{byte:x}").unwrap();
                             }
                             id
                         } else {