UPSTREAM: <drop>: Exclude awsmachinepools from OpenShift manifests

Use patchesStrategicMerge to remove awsmachinepool CRD and webhooks
from the OpenShift manifests.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
Signed-off-by: Hongkai Liu <hongkailiu@users.noreply.github.com>

Author: hongkailiu