Test apps against PHP8.2 (nightly)

[ChristophWurst]

Describe the task

To lower the chaos we had with PHP8.1, let's start testing PHP8.2 ASAP.

Ref https://github.com/shivammathur/setup-php#tada-php-support
Ref nextcloud/server#32595
Ref nextcloud/server#29287

Affected components

• Calendar Add PHP8.2 linting calendar#4249
• Calendar Resource Management Add PHP and XML linters calendar_resource_management#72
• Contacts Add PHP8.2 linting contacts#2762
• Mail Add PHP8.2 to CI matrix mail#6558

To do for each app

• Patch server to allow PHP8.2
• Patch info.xml to allow PHP8.2
• Include PHP8.2 in the CI lint matrix
• Include PHP8.2 in the CI test matrix, possibly allow the job to fail
• Fix any incompatibilities as they pop up

[ChristophWurst]

Mail has shown that CI installation and test execution works. We can test 8.2 today 👍