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-command/build.rs

@@ -4,7 +4,7 @@ fn main() -> shadow_rs::SdResult<()> {
     // Look up the current Git commit ourselves instead of relying on shadow_rs,
     // because shadow_rs does it in a really slow-to-compile way (it builds libgit2)
     let hash = get_git_hash().unwrap_or_default();
-    println!("cargo:rustc-env=NU_COMMIT_HASH={}", hash);
+    println!("cargo:rustc-env=NU_COMMIT_HASH={hash}");
 
     shadow_rs::new()
 }