[ty] Only print dashed line for failing tests (#22080)

crates/ty_test/src/lib.rs

@@ -147,11 +147,11 @@ pub fn run(
                 "{}='{escaped_test_name}' cargo test -p ty_python_semantic --test mdtest -- {test_name}",
                 EnvVars::MDTEST_TEST_FILTER,
             );
+
+            println!("\n{}\n", "-".repeat(50));
         }
     }
 
-    println!("\n{}\n", "-".repeat(50));
-
     assert!(!any_failures, "Some tests failed.");
 
     Ok(())