Workflow to delete old AMIs

[richardcase]

/kind feature

Describe the solution you'd like

Create a periodic GHA workflow that will delete AMIs that the project no longer supports.

Anything else you would like to add:
[Miscellaneous information that will assist in solving the issue.]

Environment:

• Cluster-api-provider-aws version:
• Kubernetes version: (use kubectl version):
• OS (e.g. from /etc/os-release):

[richardcase]

/assign
/triage accepted
/priority important-soon

[richardcase]

I have some code for this already and so will pick it up.

[k8s-triage-robot]

This issue is labeled with priority/important-soon but has not been updated in over 90 days, and should be re-triaged.
Important-soon issues must be staffed and worked on either currently, or very soon, ideally in time for the next release.

You can:

• Confirm that this issue is still relevant with /triage accepted (org members only)
• Deprioritize it with /priority important-longterm or /priority backlog
• Close this issue with /close

For more details on the triage process, see https://www.kubernetes.dev/docs/guide/issue-triage/

/remove-triage accepted