Update of the AWS EKS Kubernetes clusters to 1.26

ci.jenkins.io repo.aws.jenkins.io

[Final Message] The operation finished successfully at 16:45 UTC.

[Initial Message] An upgrade of the AWS EKS Kubernetes clusters from 1.25 to 1.26 is scheduled the Monday 06 November 2023 at 15:00 UTC.

Expected impact on ci.jenkins.io:

• Usual plugin build workloads using Linux containers will be run in DigitalOcean clusters
• No BOM builds can be run until the operation is finished

More details in https://github.com/jenkins-infra/helpdesk/issues/3683#issuecomment-1794913444.