burn_in_tests.py shouldn't construct a suite.Suite for dbtest.yml

The changes from ef8733f as part of SERVER-39986 made it so the dbtest executable is no longer included in the artifacts tarball. burn_in_tests.py constructs a suite.Suite for the dbtest.yml suite file, which causes it to try and invoke dbtest --list to get the names of all of the test suites. Since it isn't possible to burn-in a new dbtest test suite anyway, we should have burn_in_tests.py specify an appropriate test_kind filter to resmokelib.suitesconfig.create_test_membership_map() to avoid constructing the suite.Suite.