remove some deprecated code

nvim/.config/nvim/vendor/nvim-treesitter/lua/nvim-treesitter/caching.lua

@@ -31,7 +31,6 @@ function M.create_buffer_cache()
         on_detach = function()
           cache.clear_buffer(bufnr)
           loaded_buffers[bufnr] = nil
-          return true
         end,
         on_reload = function() end, -- this is needed to prevent on_detach being called on buffer reload
       })

nvim/.config/nvim/vendor/nvim-treesitter/lua/nvim-treesitter/compat.lua

@@ -25,15 +25,11 @@ function M.get_node_text(node, bufnr)
 end
 
 function M.require_language(lang, opts)
-  return (ts.language.add or ts.language.require_language)(lang, opts)
+  return ts.language.add(lang, opts)
 end
 
 function M.flatten(t)
-  if vim.fn.has "nvim-0.11" == 1 then
     return vim.iter(t):flatten():totable()
-  else
-    return vim.tbl_flatten(t)
-  end
 end
 
 return M