Revert "Set Vanilla 2.4 jobs as non-voting (broken heat master)"

This reverts commit 008b66a55dc57fa4390145384cf7716e410b292f.

Change-Id: I0aabf59eea0bf3193c2db78018b2ea560ab881f8
Merge "Revert "Set Vanilla 2.4 jobs as non-voting (broken heat master)""