clippy: fix warnings from uninlined_format_args

examples/basic.rs

@@ -25,5 +25,5 @@ fn main() {
         },
     );
 
-    println!("{}", grid);
+    println!("{grid}");
 }

examples/tabs.rs

@@ -28,5 +28,5 @@ fn main() {
         },
     );
 
-    println!("{}", grid);
+    println!("{grid}");
 }

tests/test.rs

@@ -204,7 +204,7 @@ fn possible_underflow() {
         },
     );
 
-    println!("{}", grid);
+    println!("{grid}");
 }
 
 #[test]