chore: Apply clippy fix in clippy-tracing integration tests

Every time my pre-commit hook does `cargo clippy --fix` it does this
change, and everytime I dont commit it. But its getting annoying, so
here it is.

Signed-off-by: Patrick Roy <[email protected]>

Author: roypat

src/clippy-tracing/tests/integration_tests.rs

@@ -191,7 +191,7 @@ fn exclude() {
                             lhs + rhs\n}";
 
     let dir_path = format!("/tmp/{}", Uuid::new_v4());
-    let _dir = std::fs::create_dir(&dir_path).unwrap();
+    std::fs::create_dir(&dir_path).unwrap();
 
     dbg!(&dir_path);