删除 Lang.timer (#5537)

HMCLCore/src/main/java/org/jackhuang/hmcl/util/Lang.java

@@ -419,26 +419,6 @@ public final class Lang {
             action.accept(it1.next(), it2.next());
     }
 
-    private static Timer timer;
-
-    public static synchronized Timer getTimer() {
-        if (timer == null) {
-            timer = new Timer(true);
-        }
-        return timer;
-    }
-
-    public static synchronized TimerTask setTimeout(Runnable runnable, long delayMs) {
-        TimerTask task = new TimerTask() {
-            @Override
-            public void run() {
-                runnable.run();
-            }
-        };
-        getTimer().schedule(task, delayMs);
-        return task;
-    }
-
     public static Throwable resolveException(Throwable e) {
         if (e instanceof ExecutionException || e instanceof CompletionException)
             return resolveException(e.getCause());