patch 8.2.0783: libvterm code lags behind the upstream version

Problem:    Libvterm code lags behind the upstream version.
Solution:   Include revisions 728 - 729.
diff --git a/src/libvterm/t/harness.c b/src/libvterm/t/harness.c
index 75869d7..e28bb7d 100644
--- a/src/libvterm/t/harness.c
+++ b/src/libvterm/t/harness.c
@@ -47,6 +47,7 @@
     { "Tab",   VTERM_KEY_TAB },
     { "Enter", VTERM_KEY_ENTER },
     { "KP0",   VTERM_KEY_KP_0 },
+    { "F1",    VTERM_KEY_FUNCTION(1) },
     { NULL,    VTERM_KEY_NONE },
   };
   int i;