Describe the bug
After update from v21.04 to v21.08, I am unable to log in :

InvalidArgumentException
View [auth.forms.login.standard] not found. (View: /var/www/BookStack/resources/views/auth/login.blade.php) 

auth.forms.login.standard was not found.
Are you sure the view exists and is a .blade.php file?

I'm the only user on my instance.
I followed the update documentation (https://www.bookstackapp.com/docs/admin/updates/).

Expected behavior
After clearing cache, I expected to be able to log in

Your Configuration (please complete the following information):
Environment information

• Exact BookStack Version (Found in settings): v21.08
• PHP Version: 7.3.29-1~deb10u1
• Hosting Method (Nginx/Apache/Docker): Nginx