Epic: Drupal 10 readiness

Lab snippet with a full set of instructions on how to scrape and claw a drupal 10+civi install into existence:

https://lab.civicrm.org/-/snippets/84

• Requires php 8.1 core#3181 (closed)
• Requires symfony 6 (this currently prevents even downloading the civi files even if you try really hard) core#2316 (closed) / PR https://github.com/civicrm/civicrm-core/pull/24132
  • Hooks defined by getSubscribedEvents don't work: core#3802 (closed)
  • Composer-compile-lib restricts to symfony 5 / PR https://github.com/civicrm/composer-compile-lib/pull/5
  • Miscellaneous other composer.json updates - see the lab snippet above.
    • Why does cache/integration-tests need to be in a prod install? Can it be in require-dev instead? PR: https://github.com/civicrm/civicrm-core/pull/25054
    • https://github.com/civicrm/civicrm-core/pull/25499 covers these:
      • symfony/config
      • symfony/dependency-injection
      • symfony/event-dispatcher
      • symfony/filesystem
      • symfony/process
      • symfony/var-dumper
      • symfony/service-contracts
      • symfony/finder
      • psr/container
  • cv uses some deprecated symfony in bootstrap / PR: https://github.com/civicrm/cv/pull/120
    • Followup fix because the attempt to keep supporting drupal 8 doesn't work with drupal 10: https://github.com/civicrm/cv/pull/126
    • core loadBoostrap(), needed e.g. for cv. https://github.com/civicrm/civicrm-core/pull/24133
  • similarly CRM_Utils_System_Drupal8 - https://github.com/civicrm/civicrm-core/pull/23302
  • financialacls core extension: core#3184 (closed)
• Requires guzzle 7 (I think this is easy) #171 (closed) / PR: https://github.com/civicrm/civicrm-core/pull/22918
• Requires psr/log 2.0. PR: https://github.com/civicrm/civicrm-core/pull/23409
• Deprecation prevents civicrm-setup from running (already PR'd): https://github.com/civicrm/civicrm-core/pull/21809 / #167 (closed)
• civicrm-drupal-8 won't enable because it doesn't declare it is compatible
  • PR: https://github.com/civicrm/civicrm-drupal-8/pull/73
• civicrm-drupal-8 civicrmtheme submodule won't enable because it doesn't declare it is compatible
  • PR: https://github.com/civicrm/civicrm-drupal-8/pull/73
• For running unit tests:
  • phpunit9 support: https://github.com/civicrm/civicrm-core/compare/master...demeritcowboy:civicrm-core:phpunit9?expand=1 along with composer require yoast/phpunit-polyfills
  • deprecated theme for mink tests: https://github.com/civicrm/civicrm-drupal-8/pull/76
    • Possibly move this file to a community-maintained drupal module? It needs to be in a drupal module. Not much uses it currently - civicrm_entity and 2 extensions.

Timewise it would be cool to have something at least installable for Drupalcon (Apr 25).

cc: @KarinG @jackrabbithanna