Umbrella issue: Onboarding ppc64le build cluster to k8s community's Prow

[Rajalakshmi-Girish]

An Umbrella issue to track work items related to adding ppc64le build cluster to Kubernetes Prow infra.

• Create an IBM account and hand over to cncf(add them as admin)
• Create k8s cluster on ppc64le using an automation scripts(TF+ansible)
• Add the kubeconfig yaml to this GCP Secret Manager Resource
• Add created k8s cluster into community prow infra: add ppc64le cluster to prow #7862
• BOSKOS setup Update boskos deployments on ibm-ppc64le cluster #7886, Configure boskos resources for ibm-ppc64le cluster #7933
• Setup ESO and gcp external secrets fix external secrets for new cluster #7883
• Add ClusterSecretStore for IBM provider's Secrets Manager and two external secrets k8s-infra-ssh-key and k8s-infra-ibmcloud-iam fix ibm build cluster secrets #7914 Add ClusterSecretStore for IBM provider's Secrets Manager #7904 Change of external secret ID in ppc64le build cluster #7936
• Add terraform code for bringing up k8s build cluster on ibmcloud: Add terraform for provisioning power build cluster on ibmcloud #7889
• Terraform for k8s-power-conformance job on ibmcloud: Terraform for k8s-power-conformance job on ibmcloud #7947

Ref: sig-k8s-infra slack thread- https://kubernetes.slack.com/archives/CCK68P2Q2/p1739359083466129

[Rajalakshmi-Girish]

/cc @upodroid @mkumatag @Prajyot-Parab @Amulyam24

[kishen-v]

/cc