Update kernel to tip of 'cos/main-R125-cos-6.12'

BUG=b/444470240
TEST=presubmit,validation
RELEASE_NOTE=Updated the Linux kernel to v6.12.46.

Change-Id: Id94af847b2b5d9470fa2102503a0d890d287a29b
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/111202
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Kevin Berry <kpberry@google.com>