docs: Improve CAS to Karpenter migration steps for clarity and automation

[mozammil89]

Fixes #N/A

Description

• Added CloudFormation template to automate setup of IAM role, policy, and interruption queue for EC2 events.
• Refined security group tagging, separating SG configurations for Launch Templates for better clarity.
• Simplified Karpenter deployment by passing node affinity settings directly to the Helm chart, eliminating the need for manual CRD installation.
• Made minor updates to improve overall readability and clarity in the documentation.

How was this change tested?

• Doc updates tested locally with hugo server
• Dry-run of steps in an existing EKS cluster with managed node group

Does this change impact docs?

• Yes, PR includes docs updates
• Yes, issue opened: #
• [] No

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

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[mozammil89]

@mariuskimmina Thank you for reviewing PR. I've addressed your review comments. Could you please recheck and let me know if further feedback is required? If everything looks good, kindly approve the PR.

[mozammil89]

I've addressed all the review comments.