[Bug] CORS issue with manifest.json file in Neptune Notebook

## Description

I see error in the browser console for a CORS error accessing the `manifest.json` file.

> Access to manifest at 'https://{region}.console.aws.amazon.com/sagemaker/home?region={region}¬ebookState={notebook_state}/notebook-instances/openNotebook/{notebook_name}' (redirected from 'https://{notebook_name}.notebook.{region}.sagemaker.aws/proxy/9250/explorer/manifest.json') from origin 'https://{notebook_name}.notebook.{region}.sagemaker.aws' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

I noticed it seems to be redirected from the URL I expected to some other URL. This doesn't happen when I execute a fetch directly for the manifest file. Perhaps this occurs because the manifest is loaded through a relative URL rather than absolute.

## Environment

- OS: macOS 14.6.1
- Browser: Arc
- Graph Explorer Version: 1.10.0
- Graph Database & Version: Amazon Neptune 1.3.2.1

## Steps to Reproduce

1. Open Graph Explorer from an Amazon Neptune Notebook
2. Open the browser developer console
3. Switch to the console tab or network tab to see the errors

## Expected Behavior

No CORS error should occurr

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