patch 8.2.0784: libvterm code lags behind the upstream version

Problem:    Libvterm code lags behind the upstream version.
Solution:   Include revisions 730 - 733.

src/libvterm/t/harness.c

@@ -483,6 +483,9 @@ int main(int argc UNUSED, char **argv UNUSED)
     if(streq(line, "INIT")) {
       if(!vt)
         vt = vterm_new(25, 80);
+
+      // Somehow this makes tests fail
+      // vterm_output_set_callback(vt, term_output, NULL);
     }
 
     else if(streq(line, "WANTPARSER")) {