No longer force close the song player window when exporting a song

Author: RaphiMC

src/main/java/net/raphimc/noteblocktool/frames/ListFrame.java

@@ -161,7 +161,6 @@ public void mouseClicked(MouseEvent e) {
         });
         GBC.create(buttonPanel).gridx(6).insets(5, 5, 5, 5).anchor(GBC.LINE_START).add(this.exportButton, () -> {
             this.exportButton.addActionListener(e -> {
-                SongPlayerFrame.close();
                 this.setEnabled(false);
                 final int[] rows = this.table.getSelectedRows();
                 List<LoadedSong> songs = new ArrayList<>();

src/main/java/net/raphimc/noteblocktool/frames/SongPlayerFrame.java

@@ -60,10 +60,6 @@ public static void open(final Song song) {
         });
     }
 
-    public static void close() {
-        if (instance != null) instance.dispose();
-    }
-
 
     private final Song song;
     private final Timer updateTimer;