Issue #3439440 by nicxvan, Binoli Lalani, longwave: Remove country support from DateFormatter

core/lib/Drupal/Core/Datetime/DateFormatter.php

@@ -117,7 +117,6 @@ public function format($timestamp, $type = 'medium', $format = '', $timezone = N
     // Create a DrupalDateTime object from the timestamp and timezone.
     $create_settings = [
       'langcode' => $langcode,
-      'country' => $this->country(),
     ];
     $date = DrupalDateTime::createFromTimestamp($timestamp, $this->timezones[$timezone], $create_settings);
 
@@ -347,8 +346,13 @@ protected function dateFormat($type, $langcode) {
    *
    * @return string
    *   The config setting for country.default.
+   *
+   * @deprecated in drupal:10.3.0 and is removed from drupal:11.0.0. There will be a contrib replacement. See https://www.drupal.org/node/3439484
+   *
+   * @see https://www.drupal.org/node/3439484
    */
   protected function country() {
+    @trigger_error('Calling ' . __METHOD__ . '() is deprecated in drupal:10.3.0 and is removed from drupal:11.0.0. There is no replacement. See https://www.drupal.org/node/3439484', E_USER_DEPRECATED);
     if ($this->country === NULL) {
       $this->country = \Drupal::config('system.date')->get('country.default');
     }