The `copilot.suggestion.is_visible()` call returns incorrect state

[dokmic]

In some cases, when suggestions are accepted programmatically (like the super-tab behavior), the is_visible function incorrectly returns a truthy value.

Reproduction Path

1. Use the following configuration:

   ~/.config/nvim/init.lua

   local lazypath = vim.fn.stdpath("data") .. "/lazy/lazy.nvim"
   if not (vim.uv or vim.loop).fs_stat(lazypath) then
     local lazyrepo = "https://github.com/folke/lazy.nvim.git"
     local out = vim.fn.system({ "git", "clone", "--filter=blob:none", "--branch=stable", lazyrepo, lazypath })
     if vim.v.shell_error ~= 0 then
       vim.api.nvim_echo({
         { "Failed to clone lazy.nvim:\n", "ErrorMsg" },
         { out, "WarningMsg" },
         { "\nPress any key to exit..." },
       }, true, {})
       vim.fn.getchar()
       os.exit(1)
     end
   end
   vim.opt.rtp:prepend(lazypath)
   
   vim.g.mapleader = " "
   vim.g.maplocalleader = "\\"
   
   require("lazy").setup({
     spec = {
       {
         {
           "zbirenbaum/copilot.lua",
           cmd = "Copilot",
           build = ":Copilot auth",
           event = "BufReadPost",
           opts = {
             suggestion = {
               auto_trigger = true,
               keymap = {
                 accept = false,
               },
             },
             panel = { enabled = false },
           },
         },
       },
     },
     install = { colorscheme = { "habamax" } },
     checker = { enabled = true },
   })
   
   vim.keymap.set({ "i", "s" }, "<Tab>", function()
     local copilot = require("copilot.suggestion")
   
     vim.notify(string.format("is_visible() => %s", tostring(copilot.is_visible())), vim.log.levels.INFO)
   
     if copilot.is_visible() then
       copilot.accept()
     else
       vim.api.nvim_feedkeys(vim.api.nvim_replace_termcodes("<Tab>", true, false, true), "n", false)
     end
   end)
   

2. Use the following file:

   ~/test.ts

   const test = () => {
     return new Promise((resolve) => {
       setTimeout(() => {
         resolve('done');
       });
     });
   }
   

3. Open the file at the 6th line in insert mode:

   nvim +'normal 6Gw' +startinsert ~/test.ts

4. Press <Tab> two or more times.

5. Open diagnostic messages via :messages

Expected Behavior

• Tabs are being inserted as many times as the corresponding key is pressed.
• The is_visible() function returns a falsy value:

  is_visible() => nil
  is_visible() => nil
  

Actual Behavior

• There is only one tab inserted.
• The is_visible() function returns a truthy value.

  is_visible() => nil
  is_visible() => 5