fix superflous assert()

Author: staabm

src/TextUI/Command/Commands/VersionCheckCommand.php

@@ -41,8 +41,6 @@ public function execute(): Result
 
         $latestCompatibleVersion = $this->downloader->download('https://phar.phpunit.de/latest-version-of/phpunit-' . $this->majorVersionNumber);
 
-        assert($latestCompatibleVersion !== false);
-
         $notLatest           = version_compare($latestVersion, $this->versionId, '>');
         $notLatestCompatible = false;