Merge 9.3.22, resolve merge conflicts, and update lockfile and dev versions.

composer.lock

composer/Metapackage/CoreRecommended/composer.json

core/assets/scaffold/files/default.services.yml

core/composer.json

core/core.services.yml

core/lib/Drupal.php

core/lib/Drupal/Core/Template/Loader/FilesystemLoader.php

core/modules/help_topics/src/HelpTopicTwigLoader.php

...modules/system/tests/src/Kernel/Theme/TwigIncludeTest.php

sites/default/default.services.yml