EX-7423 tests: skip recovery-mds-scale/failover_mds

EX-7423 tests: skip recovery-mds-scale/failover_mds

Put recovery-mds-scale/failover_mds to the always_except
list until LU-16671 has been fixed.

Test-Parameters: trivial testlist=recovery-mds-scale
Signed-off-by: Alex Deiter <adeiter@tintri.com>
Change-Id: Id6bf929a71c3e7d6a190d4c971120f0b93159393
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/51718
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>