OAuth external account linking triggers fatal error on PHP 8

After setting OAuth keys, attempting to link external account via OAuth (either through UCP or while registering) causes PHP fatal error:
Fatal error: Uncaught TypeError: array_key_exists(): Argument #2 ($array) must be of type array, phpbb\di\service_collection given in [ROOT]\phpbb\auth\provider\oauth\oauth.php on line 455
TypeError: array_key_exists(): Argument #2 ($array) must be of type array, phpbb\di\service_collection given in [ROOT]\phpbb\auth\provider\oauth\oauth.php on line 455