Merge branch '5.4' into 6.4

* 5.4:
  [Router] Discard in-memory cache of routes when writing the file-based cache
  [Security] Verify Hungarian translation
  force HTTP 1.1 for Mailgun API requests
  [String] Revert "Fixed u()->snake(), b()->snake() and s()->snake() methods"
  normalize underscores in snake()
  [Security][Validator] Added missing Portuguese(pt) translations
  Fixes #54550 some pt_BR translations
  Fix MockArraySessionStorage to generate more conform ids
  Bump Symfony version to 5.4.42
  Update VERSION for 5.4.41
  Update CONTRIBUTORS for 5.4.41
  Update CHANGELOG for 5.4.41

Transport/MailgunApiTransport.php

@@ -61,6 +61,7 @@ protected function doSendApi(SentMessage $sentMessage, Email $email, Envelope $e
 
         $endpoint = sprintf('%s/v3/%s/messages', $this->getEndpoint(), urlencode($this->domain));
         $response = $this->client->request('POST', 'https://'.$endpoint, [
+            'http_version' => '1.1',
             'auth_basic' => 'api:'.$this->key,
             'headers' => $headers,
             'body' => $body->bodyToIterable(),