Add Drupal 11 support, remove Drupal 8/9 support

Problem/Motivation

Drupal 11 first alpha has been released and both Drupal 8 and 9 have been EOL for many months, so release support needs an update.

Same for Drush 13 vs 11 and lower.

Proposed resolution

• Add D11 with Drush 12/13 support
• Drop Drupal 8 support
• Drop Drupal 9 support
• Drop Drush 11 and lower support

Remaining tasks

Do it.

User interface changes

None.

API changes

None.

Data model changes

None.