[12.x] [meta] Requirements for tagging Drupal 12.0.0-beta1

Must-haves prior to tagging 12.0.0-beta1

Release notes: [#]

1. Fully support PHP versions above the Drupal 11 minimum.
2. Update or decouple/remove PHP (Composer) dependencies.
   • Symfony:
     • Update to Symfony 8: [#]
     • Support and recommend Symfony 8.1: [#]
   • PHPUnit:
     • PHPUnit 11 (or 12?) compatibility #3418267: [meta] Support PHPUnit 11 in Drupal 11
   • Doctrine
     • #3396165: [meta] Convert all core plugin types to attribute discovery
   • Re-evaluate other backend dependencies in the year prior to the release.
3. Update or decouple/remove frontend dependencies.
   • Node
   • jQuery
   • jQuery UI
   • jQuery Form legacy code:#3189416: Remove jQuery Form dependency from misc/ajax.js
   • Yarn
   • ESLint#3440225: [PP-upstream] Support eslint 9
   • Nightwatch
4. Remove all deprecated code, libraries, and BC layers.
   • Extensions:#3488826: [12.x] [Meta] Remove deprecated extensions from Drupal 12
   • #3301206: [meta] Fix incomplete/incorrect deprecations in Drupal core
   • Remove deprecated code outside deprecated modules: [#]
   • Address usage of upstream deprecations (PHP, dependencies, etc.): [#]
5. Resolve critical 11.x -> 11.x upgrade path bugs.
6. Remove old upgrade paths up to 12.x.0 and add new database dumps.
7. Resolve any significant outstanding bugs for new platform requirements (PHP, Composer, etc.)
8. Resolve any 12.0.x-only security or data integrity issues.
9. Resolve other 12.0.x-only upgrade blockers.
10. Update all dependencies (backend and frontend) to their latest versions immediately before tagging 11.0.0-beta1.
    • Composer dependencies
    • Yarn dependencies
11. Update COPYRIGHT.txt

Should-haves prior to tagging 12.0.0-beta1

These become beta targets if they are not completed by the deadline, and may contribute to other adjustments to the schedule (TBD).

1. Fix DB fixtures process:
   • #3213633: Improve DX of maintaining migration database fixtures: provide an option for creating per-table database fixtures in DbDumpcommand
   • #3082230: [meta] Convert some tests to Build tests
2. jQuery UI
   • #2158943: Add a native dialog element to deprecate the jQuery UI dialog
   • #3076171: Provide a new library to replace jQuery UI autocomplete
3. Ensure that 12.x.x-beta1 ships with logic for warnings about future security coverage EOLs (both for the LTS version of Drupal itself, and for PHP versions, with dates hard coded as needed).
   • #3378393: Hardcode security coverage EOL dates for Drupal 10.last-1 and 10.last
   • #3361728: Make 10.x EOL warning better than the 9.5.x one
4. Backbone:#3145958: [META] Re-evaluate use of Backbone.js in core (marked internal in Drupal 10)
5. Disruptive issues:
6. Other issues TBD.