Fix broken test is deleted comment

crates/tools/src/main.rs

@@ -57,7 +57,7 @@ fn install_tests(tests: &HashMap<String, Test>, into: &str, mode: Mode) -> Resul
         // ok is never actually read, but it needs to be specified to create a Test in existing_tests
         let existing = existing_tests(&tests_dir, true)?;
         for t in existing.keys().filter(|&t| !tests.contains_key(t)) {
-            // panic!("Test is deleted: {}", t);
+            panic!("Test is deleted: {}", t);
         }
 
         let mut new_idx = existing.len() + 1;