patch 8.1.0763: nobody is using the Sun Workshop support

Problem:    Nobody is using the Sun Workshop support.
Solution:   Remove the Workshop support.
diff --git a/src/gui_motif.c b/src/gui_motif.c
index b6c140b..3f35409 100644
--- a/src/gui_motif.c
+++ b/src/gui_motif.c
@@ -698,8 +698,7 @@
     XtVaSetValues(shell, XmNmappedWhenManaged, mappedWhenManaged, NULL);
 }
 
-#if defined(FEAT_MENU) || defined(FEAT_SUN_WORKSHOP) \
-	|| defined(FEAT_GUI_DIALOG) || defined(PROTO)
+#if defined(FEAT_MENU) || defined(FEAT_GUI_DIALOG) || defined(PROTO)
 
 /*
  * Encapsulate the way an XmFontList is created.