fix(eks): migrate all AMI types from AL2 to AL2023 for K8s 1.33+

[musa-asad]

Description of the issue

EKS test clusters use deprecated AL2 AMI types which are no longer supported on K8s 1.33+. Additionally, AL2023 managed node groups default to IMDS hop limit 1, blocking pod IMDS access and breaking Container Insights.

Description of changes

1. Migrate AMI types to AL2023:

   • AL2_x86_64 → AL2023_x86_64_STANDARD
   • AL2_ARM_64 → AL2023_ARM_64_STANDARD
   • AL2_x86_64_GPU → AL2023_x86_64_NVIDIA
   • Updated in: test matrix JSON, generator, all variables.tf defaults
   • Replaced hardcoded ami_type in main.tf with var.ami_type

2. Fix IMDS access for pods on AL2023:

   • Added aws_launch_template with http_put_response_hop_limit = 2
   • Removed disk_size from node groups (incompatible with launch templates)

3. Add host_network = true to daemonset pod specs:

   • AL2023 hop limit 1 blocks IMDS from pods without hostNetwork
   • Production helm/add-on already sets hostNetwork; test terraform was missing it

License

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Tests

https://github.com/aws/amazon-cloudwatch-agent/actions/runs/25810039514

[Paamicky]

1. I think a little explanation to why efa cluster uses a different mechanism for access entries authentication_mode = "API" rather than access_config used by all other clusters would be helpful for the future
2. Multiple files have 3-4 blank lines added at the end. Cosmetic but worth cleaning.

[musa-asad]

Thanks for the review!

1. authentication_mode vs access_config: They're actually the same thing — authentication_mode = "API" is set inside the access_config block on all clusters. The EFA cluster uses the same pattern:

   access_config {
     authentication_mode = "API"
   }

   If the formatting looks different, it's just HCL style variation — functionally identical across all clusters. I'll double-check the EFA file to make sure it's consistent.

2. Trailing blank lines: Will clean those up. Thanks for catching it.