Drupal 11 development has reached a point where the system requirements are being raised in the development branch. To prepare core developers for this and to inform the community at large, we are announcing the following requirements for Drupal 11. … Drupal 11 will require PHP 8.3 and older versions of PHP are not supported. … The minimum database requirements for backends supported by Drupal 11 are MySQL 8.0 …
Drupal 11 is now open for development, Drupal 10.3.x is branched
Starting today, the Drupal 11.x branch is used for building the next major Drupal version, Drupal 11. This means that major version specific changes can now happen on the Drupal 11.x branch. This includes dependency and requirements updates and removal of deprecated API and extensions. Details are available in the allowed changes during Drupal core release cycle document. Drupal 11 is planned to be released either on the week of June 17, week of July 29 or week of December 9, 2024, depending on when beta requirements are completed.
Source: Drupal 11 is now open for development, Drupal 10.3.x is branched