fix(btags): do not use "--excmd=combine" on MacOS

Author: ibhagwan

lua/fzf-lua/providers/tags.lua

@@ -201,7 +201,7 @@ M.btags = function(opts)
   -- Used as fallback to pipe the tags into fzf from stdout
   opts._btags_cmd = string.format("%s %s %s",
     opts.ctags_bin or "ctags",
-    opts.ctags_args or "-f - --excmd=combine",
+    opts.ctags_args or "-f - " .. (utils.is_darwin() and "" or "--excmd=combine"),
     libuv.shellescape(opts.filename))
   if opts.ctags_autogen then
     opts.cmd = opts.cmd or opts._btags_cmd