Pass the jid to post_install_hook

[kassio]

This will enable users to handle the windows opened to run the jobs,

require'lspinstall'.post_install_hook = function(jid)
  local channel_info = vim.api.nvim_get_chan_info(jid)
  local winid = vim.fn.bufwinid(channel_info.buffer)
  vim.api.nvim_win_close(winid, true)
end