Following Ubuntu EKS images now running on Jammy (22.04) post, AWS EKS 1.29 images are now available on both Jammy (22.04) and Focal (20.04).
You can find Focal EKS 1.29 images with AWSCLI:
aws ssm get-parameters --names /aws/service/canonical/ubuntu/eks/20.04/1.29/stable/current/amd64/hvm/ebs-gp2/ami-id