I tried the steps you suggested to no avail. I’ve even tried completely emptying wp-content. If I go directly to https://mysite/wp-admin I get prompted to update my database but if I click the button to do so it triggers the same error — Uncaught Error: Class ‘WP_Application_Passwords’ not found
I’ve confirmed that the class is there (wp-includes/class-wp-application-passwords.php).