Blacklist trigger_initial_stable_checkpoint.js from replica_sets_multiversion

The test does an unclean shutdown on the only node in the replica set, which means that it can fail to get the proper fcv document into the stable checkpoint before it shuts down, which will result in an error during startup.

Since this test is testing soemthing internal to a single node, there is only one node in the replica set, and the test also exists on v4.2, blacklisting it will not reduce our test coverage.