Remove linux_memcheck from commit queue

It seems hopelessly broken, as no other project is using/maintaining it anymore

No-Try: True
Change-Id: I2affd8e68a9aecdd2de2cd10fee11afb2f1a390a
Reviewed-on: https://chromium-review.googlesource.com/c/1301502Reviewed-by: Patrik Höglund <phoglund@chromium.org>
Commit-Queue: Oleh Prypin <oprypin@chromium.org>

infra/config/cq.cfg

@@ -35,7 +35,6 @@ verifiers {
         name: "linux_gcc"
         experiment_percentage: 100
       }
-      builders { name: "linux_memcheck" }
       builders { name: "linux_tsan2" }
       builders { name: "linux_asan" }
       builders { name: "linux_msan" }