Convert font image straight to QIcons

Fixes a compile error with recent Qt6 versions

render.h

@@ -20,10 +20,9 @@
 #ifndef RENDER_H
 #define RENDER_H
 
-#include <QBitmap>
 #include <QColor>
+#include <QIcon>
 #include <QImage>
-#include <QPixmap>
 
 #include "decode.h"
 
@@ -34,11 +33,10 @@ public:
 	~TeletextFontBitmap();
 
 	QImage *image() const { return s_fontImage; }
-	QBitmap charBitmap(int c, int s) const { return s_fontBitmap->copy((c-32)*12, s*10, 12, 10); }
+	QIcon charIcon(int c, int s) const;
 
 private:
 	static int s_instances;
-	static QBitmap* s_fontBitmap;
 	static QImage* s_fontImage;
 };