[backport v2.10.1] Invalid data entered from nodepool SSH Key dropdown when provisioning EKS

[github-actions]

This is a backport issue for #12877, automatically created via GitHub Actions workflow initiated by @gaktive

Original issue body:

Setup

• Rancher version: v2.10-c4944b3ca0b39c474121df9e7ef31f7aff4e4f7a-head and dashboard release-2.10 5218335
• Browser type & version: any

Describe the bug
When provisioning an EKS cluster from Rancher the user can select a ssh-key pair stored on AWS to be added to the node instances within their nodepool. The dropdown menu offers valid key-ids but once it's selected and saved the nodepool is going to be created or updated but it fails and then the error occurs.

To Reproduce
Try to provision or edit any EKS cluster and select a ssh-key from the dropdown, then save and check status of the cluster.

Result
It seems instead of the key-id it uses a map structure like map[CreateTime:2024-12-12T12:47:08.327Z...
Error from eks-operator:

time="2024-12-12T13:10:18Z" level=error msg="error syncing 'cattle-global-data/c-mmmcg': handler eks-controller: error creating nodegroup: operation error EKS: CreateNodegroup, https response error StatusCode: 400, RequestID: cd41cce3-cd4a-45c7-a437-ecabee27dc0a, InvalidRequestException: The key pair 'map[CreateTime:2024-12-12T12:47:08.327Z KeyFingerprint:6b:9b:79:b1:30:d3:68:c1:32:49:6c:a3:08:90:c6:3f:3b:64:4e:40 KeyName:thehejik KeyPairId:key-0eeec448f711ec685 KeyType:rsa Tags:[]]' does not exist, requeuing"

Expected Result
The provisioning or update should be successful and ssh-key should be added.

Screenshots

[izaac]

Rancher version: v2.10-87b97590837835650d045937b669ee0206604758-head
UI version: release-2.10 d5b785b

The public ssh key is correctly formatted in the POST ec2SshKey key when creating the EKS cluster.
Once the cluster is available or while it is still provisioning I am able to see the correct key without anything else just the same string in the POST;s ec2SshKey

The last part is visual as apparently the GET returned by Amazon looks encrypted.

Closing as validated. ✅