0.4.0: Persistence, PHP 7.4+

• Heads up: Require xp-forge/sessions version 4.0+ - @thekid
• Heads up: Dropped support for PHP < 7.4, see xp-framework/rfc#343
  (@thekid)
• Added PHP 8.5 and PHP 8.6 to the test matrix - @thekid