Dispatch events on a copy of the listener list

This allows for listeners to be removed/added while dispatching.

Author: weisJ

theme/src/main/java/com/github/weisj/darklaf/theme/event/ThemeEventSupport.java

@@ -43,8 +43,10 @@ public void dispatchEvent(final E event) {
     }
 
     public void dispatchEvent(final E event, final BiConsumer<T, E> consumer) {
-        listenerList.forEach(listener -> {
-            if (listener != null) consumer.accept(listener, event);
-        });
+        synchronized (listenerList) {
+            new ArrayList<>(listenerList).forEach(listener -> {
+                if (listener != null) consumer.accept(listener, event);
+            });
+        }
     }
 }