Format code per maintainer feedback

Co-authored-by: samueltardieu <44656+samueltardieu@users.noreply.github.com>

Author: Copilot

src/directed/cycle_detection.rs

@@ -47,11 +47,7 @@ where
     // Handle edge case where they meet at the start position (pure cycle, mu = 0)
     // In this case, tortoise_steps equals lam, and to satisfy mu_tilde < mu + lam,
     // we must return 0.
-    let mu_tilde = if tortoise == start {
-        0
-    } else {
-        tortoise_steps
-    };
+    let mu_tilde = if tortoise == start { 0 } else { tortoise_steps };
     (lam, tortoise, mu_tilde)
 }