Document ROSA/ARO control plane/infra node caveats

[evanstoner]

• [ ] Include some text in the OpenShift deploy guide explaining the support stance.
• [x] ~Add infra nodes to default tolerations? Or just provide an example for managed clusters.~ #459

Suggested text:

Managed OpenShift services (e.g. ROSA, ARO, RHOIC, OSD) do not support running user workloads on control plane and infrastructure nodes. However, not deploying the sensor to some nodes in the cluster would create a gap in protection. For this reason, we recommend deploying the sensor to all nodes in the cluster by using the default tolerations. Please be aware that Red Hat site reliability engineering (SRE) may be unable to maintain your cluster's service level agreement (SLA) for availability, and you may have to remove the sensor from control plane and infrastructure nodes during troubleshooting. For more information, see the Red Hat support article Running custom workloads in OSD/ROSA control plane or infra nodes.

If you would prefer to maintain your SLA and SRE support by limiting your protection to worker nodes, override the tolerations in FalconNodeSensor to be an empty list:

apiVersion: falcon.crowdstrike.com/v1alpha1
kind: FalconNodeSensor
metadata:
spec:
  node:
    tolerations: []
# ...