Since changing ReplicaSetTests to wait until they generate their keys for signing cluster times, the execution time of the replica_sets_WT suite has almost doubled

Most of our javascript tests, except for the ones that are explicitly testing the key signing behavior, don't need to be doing the key signing. We should either skip generating keys entirely, or hard code the key we generate in test mode, or some other way win back the lost test execution time for tests that don't need strong keys.