infra: Remove builders on the 'cft' sheriff rotation from the mega CQ

These builders are very red, and seemingly never green:
https://ci.chromium.org/ui/p/chromium/g/chromium.cft/builders

So just remove them from the mega CQ. The point of the mega CQ is to
cover all bots whose regressions would lead to a revert of the CL that
regressed them. But if some builders are always very red, then they
likely never lead to reverts.

Bug: 1227778
Change-Id: I4adb88f43948b6000e9ec49384337da347921ef8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5003349
Reviewed-by: Garrett Beaty <gbeaty@google.com>
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1219187}