EKS-Cluster: Remove AWS-SDK dependency

This MR removes the AWS SDK for JavaScript dependency. We used this dependency as a transitionary step to develop the Front-End for the EKS Cluster integration. In !19045 (closed), we introduced an API Proxy to request AWS resources through our own API.

Conformity

created](https://gitlab.com/gitlab-org/gitlab/issues/new?issuable_template=Doc%20Review)

• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content