[aws-eks] Support S3 private bucket repository from helm deployment

### Use Case
Right now helm deployment only support public github repository. We need to read the repository from s3 private repo

### Proposed Solution

>
I would like to help to develop the feature but would like to hear your opinion on the approach

1. Create a s3 presign url and use the presign url to deploy the chart
`new HelmChart(this, 'cortexHelm', {
cluster: props.cluster,
chart: props.presignUrl,
namespace: props.environment.cluster.namespace,
values: overrides,
release: 'cortex'
});`

2. install S3 plugin at lambda layer: https://github.com/aws-samples/aws-lambda-layer-kubectl
Use the S3 plugin to read from S3 private repo while deploy helm chart:
Plugin link: https://github.com/hypnoglow/helm-s3

### Other

* [x] :wave: I may be able to implement this feature request
* [ ] :warning: This feature might incur a breaking change

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This is a :rocket: Feature Request

Start by tracing the HelmChart entry point and its chart property in the AWS CDK EKS deployment flow. Compare the proposed presigned S3 URL approach with the helm-s3 plugin linked in the issue, then establish the supported API and deployment behavior. Done means a private S3 repository can be consumed by Helm deployment without breaking the existing public GitHub repository path.

Written by the indexing model from the issue text.