CI: ci-awscni & ci-eks - AlreadyExistsException: Stack [eksctl-cilium-cilium-<runid>-1-cluster] already exists #29426
Description
CI failure
Creating the AWS EKS cluster during the tests ci-awscni & ci-eks fails with the following failiure:
2023-11-28 00:49:50 [ℹ] building cluster stack "eksctl-cilium-cilium-7012612170-1-cluster"
Error: failed to create cluster "cilium-cilium-7012612170-1"
2023-11-28 00:49:51 [!] 1 error(s) occurred and cluster hasn't been created properly, you may wish to check CloudFormation console
2023-11-28 00:49:51 [ℹ] to cleanup resources, run 'eksctl delete cluster --region=eu-central-1 --name=cilium-cilium-7012612170-1'
2023-11-28 00:49:51 [✖] creating CloudFormation stack "eksctl-cilium-cilium-7012612170-1-cluster": operation error CloudFormation: CreateStack, https response error StatusCode: 400, RequestID: 02c84e8b-0c98-449a-8cd6-7c5dcdfadfe9, AlreadyExistsException: Stack [eksctl-cilium-cilium-7012612170-1-cluster] already exists
Error: Process completed with exit code 1.
e.g. https://github.com/cilium/cilium/actions/runs/7012612170/job/19077439535
The issue is that the name with the pattern ${{ github.repository_owner }}-${{ github.event.repository.name }}-${{ github.run_id }}-${{ github.run_attempt }} isn't unique enough in cases where a testrun deploys a cluster in the same region twice. This is the case for eu-central-1 since #29004
https://github.com/cilium/cilium/blob/main/.github/workflows/conformance-aws-cni.yaml#L54
Proposal
a) use a different region -> fixed with #29427
b) use a unique identifier for the name of the cluster to avoid name clashes