fix(lsp): fix removed param value in add_workspace_folder (#21915)

runtime/lua/vim/lsp/buf.lua

@@ -487,7 +487,7 @@ function M.add_workspace_folder(workspace_folder)
   end
   local params = util.make_workspace_params(
     { { uri = vim.uri_from_fname(workspace_folder), name = workspace_folder } },
-    { {} }
+    {}
   )
   for _, client in pairs(vim.lsp.get_active_clients({ bufnr = 0 })) do
     local found = false