Exclude static tests for mcheck and malloc-check

mcheck and malloc-check no longer work with static binaries, so drop
those tests.

Reported-by: Samuel Thibault <samuel.thibault@gnu.org>
Tested-by: Samuel Thibault <samuel.thibault@gnu.org>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>