Remove the concurrency_simultaneous suite from v3.2

The concurrency_simultaneous suite is not running any tests on v3.2 because the runWorkloadsInParallel call is commented out: https://github.com/mongodb/mongo/blob/r3.2.9-rc1/jstests/concurrency/fsm_all_simultaneous.js#L11-L14

We should remove:

1. The fsm_all_simultaneous.js file
2. The 'concurrency_simultaneous' bits in etc/evergreen.yml