DNM cirrus: enable Spot instances for z1d.metal

[timcoding1988]

Enable AWS Spot instances for z1d.metal in podman_machine_windows_task to reduce EC2 costs by approximately 75%.
why ??

  access the same hardware at a fraction of the cost. The tradeoff: AWS can reclaim the instance with a 2-minute
  warning when capacity is needed.

reference link: https://cloudprice.net/aws/ec2/instances/z1d.metal

Checklist

Ensure you have completed the following checklist for your pull request to be reviewed:

• Certify you wrote the patch or otherwise have the right to pass it on as an open-source patch by signing all
  commits. (git commit -s). (If needed, use git commit -s --amend). The author email must match
  the sign-off email address. See CONTRIBUTING.md
  for more information.
• Referenced issues using Fixes: #00000 in commit message (if applicable)
• Tests have been added/updated (or no tests are needed)
• Documentation has been updated (or no documentation changes are needed)
• All commits pass make validatepr (format/lint checks)
• Release note entered in the section below (or None if no user-facing changes)

Does this PR introduce a user-facing change?

None

[mheon]

Sure, seems like a fine thing to try. If we do start getting frequent cancellations due to AWS capacity, we can reevaluate.

[Luap99]

does cirrus rerun automatically if that happens?

Not against it since tests generally run quick enough.

That said if this is to safe money than maybe we should also look into nested virst now that is got support in aws so we do not use these expensive bare metal instances https://aws.amazon.com/about-aws/whats-new/2026/02/amazon-ec2-nested-virtualization-on-virtual/

[Luap99]

Also if we do this why limit to this one task, I guess this should be done for every bare metal task at least of not more

[timcoding1988]

@Luap99 i cannot find the answer of retry. cirrus-ci mentioned retries on gcp. i cannot confirm with this. secondly linux bare-metal we can do that too. spot only available for windows and linux

[packit-as-a-service]

[NON-BLOCKING] Packit jobs failed. @containers/packit-build please check. Everyone else, feel free to ignore.

[timcoding1988]

@Luap99 check on the nest virt, so nest vir only avaibale in m8i.2xlarge, currently we dont have in our aws account only up to m7. meanwhile m8i.2xlarge nest virt required to enable the NestedVirtualization CPU option

[timcoding1988]

turn out we cannot trust those spot instance plans, highly unstable