fix: use nvim-api to avoid win_getid exceptions (#525)

lua/lualine/utils/notices.lua

@@ -45,7 +45,7 @@ end
 function M.show_notices()
   vim.cmd('silent! keepalt split')
 
-  local winid = vim.fn.win_getid()
+  local winid = vim.api.nvim_get_current_win()
   local bufnr = vim.api.nvim_create_buf(false, true)
   vim.api.nvim_win_set_buf(winid, bufnr)
 

lua/lualine/utils/utils.lua

@@ -90,7 +90,7 @@ end
 
 -- Check if statusline is on focused window or not
 function M.is_focused()
-  return tonumber(vim.g.actual_curwin) == vim.fn.win_getid()
+  return tonumber(vim.g.actual_curwin) == vim.api.nvim_get_current_win()
 end
 
 --- Check what's the charecter at pos