throw when a thread in thread pool has an error post-execution

Author: lucasstarsz

src/main/java/tech/fastj/systems/execution/FastJScheduledThreadPool.java

@@ -102,6 +102,8 @@ protected void afterExecute(Runnable runnable, Throwable throwable) {
             if (shouldCloseOnError) {
                 FastJEngine.forceCloseGame();
             }
+
+            throw new IllegalStateException(throwable);
         }
     }
 }