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/misc2.c b/src/misc2.c
index 0bbcb39..55a901f 100644
--- a/src/misc2.c
+++ b/src/misc2.c
@@ -3411,7 +3411,7 @@
 
 #if defined(FEAT_SESSION) || defined(FEAT_AUTOCHDIR) \
 	|| defined(MSWIN) || defined(FEAT_GUI_MAC) || defined(FEAT_GUI_GTK) \
-	|| defined(FEAT_SUN_WORKSHOP) || defined(FEAT_NETBEANS_INTG) \
+	|| defined(FEAT_NETBEANS_INTG) \
 	|| defined(PROTO)
 /*
  * Change to a file's directory.