SECRETS: Delete all secrets stored during "max_secrets" test
    
    Otherwise we will have an 507 error in case any secret is added by any
    of the tests that may be implemented in the future.
    
    Signed-off-by: Fabiano Fidêncio <fidencio@redhat.com>
    
    Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>
    Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>
    (cherry picked from commit 9ba53ac52b12e2b9fdd3981d28ae56a8fece0131)