add preventSustainClip (#856)

source/funkin/backend/scripting/events/note/NoteHitEvent.hx

@@ -11,6 +11,7 @@ final class NoteHitEvent extends CancellableEvent {
 	@:dox(hide) public var unmuteVocals:Bool = true;
 	@:dox(hide) public var enableCamZooming:Bool = true;
 	@:dox(hide) public var autoHitLastSustain:Bool = true;
+	@:dox(hide) public var clipSustain:Bool = true;
 
 	/**
 	 * Whenever a miss should be added.
@@ -145,6 +146,13 @@ final class NoteHitEvent extends CancellableEvent {
 		deleteNote = true;
 	}
 
+	/**
+	 * Prevents the sustain from being cut. Only works if the note is a sustain.
+	 */
+	public function preventSustainClip() {
+		clipSustain = false;
+	}
+
 	/**
 	 * Prevents the vocals volume from being set to 1 after pressing the note.
 	 */