Deprecation: #109027 - Move language:update command and events to EXT:core 

Description 

The language:update CLI command and the related \TYPO3\CMS\Install\Service\LanguagePackService have been moved from EXT:install to EXT:core, allowing installations to update language packs without requiring EXT:install to be installed.

Since TYPO3 v13, it is possible to run TYPO3 without EXT:install in composer based installations. However, the language:update command still required EXT:install, which made this advantage impractical for deployments that need to update language packs.

The following classes have been moved and their old class names deprecated:

• \TYPO3\CMS\Install\Command\LanguagePackCommand is now \TYPO3\CMS\Core\Command\UpdateLanguagePackCommand
• \TYPO3\CMS\Install\Service\Event\ModifyLanguagePackRemoteBaseUrlEvent is now \TYPO3\CMS\Core\Localization\Event\ModifyLanguagePackRemoteBaseUrlEvent
• \TYPO3\CMS\Install\Service\Event\ModifyLanguagePacksEvent is now \TYPO3\CMS\Core\Localization\Event\ModifyLanguagePacksEvent

The old class names are registered as aliases via ClassAliasMap and continue to work in TYPO3 v14. Event listeners registered for the deprecated event class names are still called when the new event is dispatched, with a deprecation notice triggered at runtime.

Impact 

Using the old class names will trigger a deprecation notice. The extension scanner will report usages of the deprecated class names.

The old class names will be removed in TYPO3 v15.

Affected installations 

Extensions that use one or more of the deprecated class names listed above.

Migration 

Replace the old class names with the new ones in use statements:

 <?php

 declare(strict_types=1);

 namespace MyVendor\MyExtension\EventListener;

 use TYPO3\CMS\Core\Attribute\AsEventListener;
-use TYPO3\CMS\Install\Service\Event\ModifyLanguagePacksEvent;
+use TYPO3\CMS\Core\Localization\Event\ModifyLanguagePacksEvent;

 final class MyEventListener
 {
     #[AsEventListener(
         identifier: 'my-extension/modify-language-packs',
     )]
     public function __invoke(
         ModifyLanguagePacksEvent $event,
     ): void {
         // ...
     }
 }

 <?php

 declare(strict_types=1);

 namespace MyVendor\MyExtension\EventListener;

 use TYPO3\CMS\Core\Attribute\AsEventListener;
-use TYPO3\CMS\Install\Service\Event\ModifyLanguagePackRemoteBaseUrlEvent;
+use TYPO3\CMS\Core\Localization\Event\ModifyLanguagePackRemoteBaseUrlEvent;

 final class MyOtherEventListener
 {
     #[AsEventListener(
         identifier: 'my-extension/modify-language-pack-remote-base-url',
     )]
     public function __invoke(
         ModifyLanguagePackRemoteBaseUrlEvent $event,
     ): void {
         // ...
     }
 }