Prevent installer downloading translations unnecessarily

Closes #3524389

locale_deploy.install

@@ -5,6 +5,9 @@
  * Install, update and uninstall functions for the Locale Deploy module.
  */
 
+use Drupal\Core\Installer\InstallerKernel;
+use Drupal\Core\Language\LanguageInterface;
+
 /**
  * Implements hook_install().
  */
@@ -12,6 +15,24 @@ function locale_deploy_install(bool $is_syncing): void {
   if (!$is_syncing) {
     _locale_deploy_config_fix();
   }
+
+  // Prevent install_config_download_translations() from doing unnecessary
+  // downloads during an install. This code is inspired by
+  // install_find_translations().
+  if (InstallerKernel::installationAttempted() && $is_syncing) {
+    global $install_state;
+    $files = \Drupal::service('file_system')->scanDirectory('translations://', '!drupal\.' . LanguageInterface::VALID_LANGCODE_REGEX . '\.po$!', ['recurse' => FALSE]);
+
+    foreach ($files as $uri => $file) {
+      // Strip off the file name component before the language code.
+      $langcode = preg_replace('!^(.+\.)?([^\.]+)$!', '\2', $file->name);
+      // Language codes cannot exceed 12 characters to fit into the {language}
+      // table.
+      if (strlen($langcode) <= 12) {
+        $install_state['translations'][$langcode] = $uri;
+      }
+    }
+  }
 }
 
 /**