TESTUTIL_BYPASS_VALGRIND and TESTUTIL_SLOW_MACHINE flags were previously used by our csuite testing code to bypass certain tests for the Jenkins valgrind job, and if the tests are scheduled onto a slow machine. With all csuite tests being migrated to Evergreen, the need for these 2 flags are not there.

We should evaluate the multiple csuite test programs that currently check the 2 flags, and remove them if possible.