refactor: use a better way to generate day style

lua/lualine/themes/tokyonight.lua

@@ -36,19 +36,6 @@ tokyonight.inactive = {
   c = { bg = colors.bg_statusline, fg = colors.fg_gutter },
 }
 
-if vim.o.background == "light" then
-  for _, mode in pairs(tokyonight) do
-    for _, section in pairs(mode) do
-      if section.bg then
-        section.bg = util.getColor(section.bg)
-      end
-      if section.fg then
-        section.fg = util.getColor(section.fg)
-      end
-    end
-  end
-end
-
 if vim.g.tokyonight_lualine_bold then
   for _, mode in pairs(tokyonight) do
     mode.a.gui = "bold"