Default backend update

Following the addition of the builtin backend in 4.3.0, the builtin backend is now the default in 4.4.0. If your migrations don't run correctly with 4.4.0 please open an issue. You can temporarily switch back to the phinx backend by setting Migrations.backend = 'phinx' in your config/app.php.

The phinx backend is planned for removal in the 5.0 release which will follow 4.4 after collecting feedback from the community for a few months.

What's Changed

• Start update for php 8.4 by @markstory in https://github.com/cakephp/migrations/pull/729
• Use actual Migrations version in builtin backend doc by @MasterOdin in https://github.com/cakephp/migrations/pull/733
• update stan by @LordSimal in https://github.com/cakephp/migrations/pull/734
• 4.next: add PHPUnit 11 support by @LordSimal in https://github.com/cakephp/migrations/pull/736
• Make builtin the default migrations backend by @markstory in https://github.com/cakephp/migrations/pull/738

Full Changelog: https://github.com/cakephp/migrations/compare/4.3.2...4.4.0