Update Base Image to use Amazon Linux 2023 variant

`eksbuild` version of coredns is using AL2 as base image. AL2 is going EoL on June 30th 2026.

This is a request to update the base image to AL2023.

My understanding is that https://github.com/aws/eks-distro/blob/main/EKS_DISTRO_MINIMAL_BASE_TAG_FILE needs to be updated. Supposedly it should go from `2026-01-22-1769097811.2` to something like `2026-06-09-1781048393.2023` which is one of the recent AL2023 builds.

Start with EKS_DISTRO_MINIMAL_BASE_TAG_FILE and inspect the recent Amazon Linux 2023 builds to identify the appropriate replacement for the current AL2 tag. Update the referenced base image tag, then verify that the eksbuild CoreDNS image uses the AL2023 variant.

Written by the indexing model from the issue text.