fix: add new sample mp3s for e2e tests and storybook

[lhaggar]

What
Previous mp3 test files used in Storybook and E2E tests has been removed, meaning E2E tests fail. This PR updates references to a new file, which will be self-hosted under the newskit.co.uk website. This PR will require forced merging with broken E2E and deploying through to prod. Subsequent builds should then work as normal.

I have done:

• Written unit tests against changes
• Written functional tests against the component and/or NewsKit site
• Updated relevant documentation

I have tested manually:

• The feature's functionality is working as expected on Chrome, Firefox, Safari and Edge
• The screen reader reads and flows through the elements as expected.
• There are no new errors in the browser console coming from this PR.
• When visual test is not added, it renders correctly on different browsers and mobile viewports (Safari, Firefox, small mobile viewport, tablet)
• The Playground feature is working as expected

[pp-serviceaccount]

You can preview these changes on:
Documentation Site: http://ncu-newskit-docs-pr.s3-website-eu-west-1.amazonaws.com/new-sample-mp3s-for-e2e
Storybook: http://ncu-newskit-docs-pr.s3-website-eu-west-1.amazonaws.com/new-sample-mp3s-for-e2e/storybook

[pdimova]

Just wondering what the reason is for removing these files on S3

[lhaggar]

@pdimova not 100% sure. The bucket exists but is empty. It's in the NGN dev account rather than NewsKit's, I think its the original bucket before the site origin was moved.

[JohnTParsons]

@pdimova not 100% sure. The bucket exists but is empty. It's in the NGN dev account rather than NewsKit's, I think its the original bucket before the site origin was moved.

I thought I'd moved the ncu-newskit-docs bucket from NGN to product platforms account a year ago. Not sure.

I thought NGN was just being used to save the Terraform state.