Your XenForo installation is large. If you are doing a major upgrade, you may wish to upgrade via the command line. Simply run this command and follow the on-screen instructions:
php '/var/www/vhosts/xxxxx.xxxxxx.xxx.xxx/httpdocs/library/XenForo/Install/run-upgrade.php'
You can continue with the browser-based upgrade, but large queries may cause browser timeouts that will force you to reload the page.
