runner - fix cli runtime display

Author: pareronia

src/main/python/aoc/runner/listener.py

@@ -263,7 +263,7 @@ def _format_time(self, time: int, timeout: float) -> str:
         if t < 0.001:
             runtime = colored(f"{t * 1000:7.3f}ms", color)
         else:
-            runtime = colored("{t:8.4f}s", color)
+            runtime = colored(f"{t:8.4f}s", color)
         return cast("str", runtime)