PHP 8.2 update and introduction of legacy branch

The php packages have been updated to the latest version 8.2. In addition to this, a new set of php-legacy packages have been introduced. These will follow the oldest but still actively supported PHP branch. This enables users to install the latest version but also introduces the option to use third party applications that might rely on an older version. Both branches will be kept up to date following our rolling release model. php and php-legacy can be installed at the same time as the latter uses a -legacy suffix for its binaries and configuration files.

In addition to this, the php7 packages have been removed as they reached end of life. The imap extension will no longer be provided as it relies on the c-client library which has been abandoned for many years.