Like OTA-1391, but for 4.(even-2).z -> 4.even in stable-4.even. This avoids the need to discuss the knowledge backports that make OTA-1391 sticky, because we're already doing those same backports to 4.(even-2).z to support eus-4.even. With this change, stable-4.even and eus-4.even will become functionally identical (I guess possibly freeing up space to do other things to distinguish those channels, besides withholding releases based on 4.(even-2)).