Inform operator if restarting mod_php/fpm is more likely than not to be needed after triggering an Upgrade so people are less surprised when this happens and/or to remind people that adjust these values but then later forget. :)

Options:

• An info level message in existing PhpOpcacheSetup setupcheck
• Something within updatenotification app that gets displayed on the Updater screen
• Something in Updater itself

Or:

• Just tell people to restart always 🤷‍♂️

Currently going to focus on clarifying in the documentation: nextcloud/documentation#11872

Related:

• [Bug]: error after automatic upgrade (php compatibility) #45490, [Bug]: Manual upgrade to 28.0.6.1 prompts this error #45504, among others (forum posts too)
• [Bug]: OPCache doesn't refresh when code changes #39079
• https://core.trac.wordpress.org/ticket/36455 (much bigger topic; we could make some things better with some changes with how we handle both Server and app upgrades, but there's no foolproof solution)