[backport v2.7.next1] Remove Support for AWS In-Tree Cloud Provider if Using k8s 1.27+

[github-actions]

This is a backport issue for #9204, automatically created via GitHub Actions workflow initiated by @gaktive

Original issue body:

Internal reference: SURE-6511

With Kubernetes 1.27 and up, the AWS in-tree cloud provider no longer works so we need to ensure that users upgrading from earlier versions are aware and have a way to migrate off of it.

From Hostbusters, @kinarashah is looking at how the upgrade works from the backend. @Sahota1225 & @snasovich are aware of the UI needs. We'll need to figure out the UX around this with the appropriate advance notifications prior to upgrade and then the behaviour during upgrade: having radio buttons disabled, proper dropdowns, banners, etc.

@mantis-toboggan-md knows the basic details.

[gaktive]

We may have other k8s 1.27 work that needs backporting to 2.7.x so I'm checking.

[mantis-toboggan-md]

There are RKE1 and RKE2 components to this issue.

In RKE1 the 'Amazon' cloud provider option is removed >= 1.27 (and a new one is added, see #10297)

The RKE2 portions ties in to #9110 - in the RKE2 provisioning UI the 'aws' cloud provider option is not removed for k8s >= 1.27, but instead refers to the external aws cloud provider. The UI shows a banner warning the user that they need additional configuration #9110 (comment)

[slickwarren]

tested as part of regression tests in rancher, tracked in Qase. All tests are passing on 2.7.11-head