patch 8.2.3666: libvterm is outdated

Problem:    Libvterm is outdated.
Solution:   Include patches from revision 769 to revision 789.
diff --git a/src/terminal.c b/src/terminal.c
index df1ca69..4a95a3e 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -4526,7 +4526,10 @@
   NULL,		// control
   parse_csi,	// csi
   parse_osc,	// osc
-  NULL		// dcs
+  NULL,		// dcs
+  NULL,		// apc
+  NULL,		// pm
+  NULL		// sos
 };
 
 /*