fix: replace tbl_flatten to flatten():totable() (#912)

* fix: replace tbl_flatten to flatten():totable()

- support nvim < 0.10

* fix: extract nvim version check to a variable

* fix: check if is nvim 0.11 for flatten()

lua/bufferline/ui.lua

@@ -555,7 +555,7 @@ local function to_tabline_str(component)
     table.insert(str, 1, attr[1])
     table.insert(str, #str + 1, attr[1])
   end
-  return table.concat(vim.tbl_flatten(str))
+  return table.concat(utils.tbl_flatten(str))
 end
 
 --- PREREQUISITE: active buffer always remains in view

lua/bufferline/utils/init.lua

@@ -10,6 +10,8 @@ local M = {}
 local fn, api = vim.fn, vim.api
 local strwidth = api.nvim_strwidth
 
+local isNvimEleven = vim.fn.has("nvim-0.11") == 1
+
 function M.is_test()
   ---@diagnostic disable-next-line: undefined-global
   return __TEST
@@ -275,4 +277,8 @@ else
   M.is_list = vim.tbl_isarray or vim.tbl_islist
 end
 
+function M.tbl_flatten(t)
+  return isNvimEleven and vim.iter(t):flatten(math.huge):totable() or vim.tbl_flatten(t)
+end
+
 return M