vim-patch:9.1.0618: cannot mark deprecated attributes in completion menu

Problem:  cannot mark deprecated attributes in completion menu
Solution: add hl_group to the Dictionary of supported completion fields
          (glepnir)

closes: vim/vim#15314

508e7856ec

Co-authored-by: glepnir <glephunter@gmail.com>

src/nvim/cmdexpand.c

@@ -356,6 +356,7 @@ static int cmdline_pum_create(CmdlineInfo *ccline, expand_T *xp, char **matches,
       .pum_info = NULL,
       .pum_extra = NULL,
       .pum_kind = NULL,
+      .pum_extrahlattr = -1,
     };
   }