[robot-name] Clippy says to use ('A'..='Z').contains(x) (#1001)

Author: ClashTheBunny

exercises/robot-name/tests/robot-name.rs

@@ -3,11 +3,11 @@ use robot_name as robot;
 fn assert_name_matches_pattern(n: &str) {
     assert!(n.len() == 5, "name is exactly 5 characters long");
     assert!(
-        n[0..2].chars().all(|c| c >= 'A' && c <= 'Z'),
+        n[0..2].chars().all(|c| ('A'..='Z').contains(&c)),
         "name starts with 2 uppercase letters"
     );
     assert!(
-        n[2..].chars().all(|c| c >= '0' && c <= '9'),
+        n[2..].chars().all(|c| ('0'..='9').contains(&c)),
         "name ends with 3 numbers"
     );
 }