PHP 8.2 Compatibility

[rosiel]

PHP 8.1 will be out of active support in Nov 2023; and out of security support a year after.

PHP 8.1 supports Drupal 9.5, 10.1, and 10.2 but PHP 8.2 only supports Drupal 10.1 and 10.2.

This will need to be updated:

• in testing matrices for all our components
• in Buildkit to make the containers use the newer PHP

[adam-vessey]

(whoops, was just trying to look at the milestone thing)

[rosiel]

The code is now 8.2-compliant to the best of my knowledge. Other issues (including updating our devops stuff to actually use 8.2) can be done separately. (e.g. Islandora-Devops/isle-buildkit#293)