patch 9.2.0582: GTK4: compile error when XFONTSET is defined

Problem:  GTK4: compile error when XFONTSET is defined
          (simozz)
Solution: Undefine FEAT_XFONTSET when GTK4 UI is defined
          (Foxe Chen)

fixes:  #20404
closes: #20406

Signed-off-by: Foxe Chen <chen.foxe@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/feature.h

@@ -444,6 +444,10 @@
 # else
 // #  define FEAT_XFONTSET
 # endif
+#else
+# if defined(USE_GTK4)
+#  undef FEAT_XFONTSET
+# endif
 #endif
 
 /*

src/version.c

@@ -729,6 +729,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    582,
 /**/
     581,
 /**/