Fixes to remove warnings when use phpunit 9.5.6
Fixes to remove warnings when use phpunit 9.5.6

Replace method at by withConsecutive and willReturnOnConsecutiveCalls

Signed-off-by: Vitor Mattos <ddd80347cc894536655615ccf7805ebc23683866@php.rio>

nextcloud/spreed,nextcloud/spreed,nextcloud/spreed