Kura cache gateway now schedules on bare-metal cache nodes

Fixes a bug where Kura cache endpoints in bare-metal regions (eu-central, us-east, us-west) could not serve cached artifacts. The ingress-nginx gateway pods failed to schedule on the bare-metal cache nodes because they lacked the tuist.dev/kura-cache toleration, so the region’s public cache endpoint was unreachable and the dashboard stayed stuck at “Deploying.” The gateway can now schedule on those nodes and the public cache endpoint serves correctly.