Merge branch '6.4' into 7.0

* 6.4:
  Skip Twig v3.9-dev for now
  [Validator] Update Dutch (nl) translation
  Update Albanian translations
  [Validator] Update translation
  [FrameworkBundle] Prevent silenced warning by checking if /proc/mount exists
  [VarDumper][PhpUnitBridge] Fix color detection
  prevent throwing NOT_FOUND error when tube is empty
  [Validator] Update missing validator translation for Swedish
  [FrameworkBundle] Fix eager-loading of env vars in ConfigBuilderCacheWarmer
  [Messenger] Fix failing Redis test
  [Validator] Update Italian (it) translations
  [Validator] Missing translations for Hungarian (hu) #53769
  revert to native PHP union types
  [Validator] Missing translations for Russian (ru) #53775
  fix syntax errors on PHP 7

Author: nicolas-grekas

Transport/Connection.php

@@ -182,6 +182,7 @@ public function reject(string $id): void
     public function getMessageCount(): int
     {
         try {
+            $this->client->useTube($this->tube);
             $tubeStats = $this->client->statsTube($this->tube);
         } catch (Exception $exception) {
             throw new TransportException($exception->getMessage(), 0, $exception);