Remove the Audience Segmentation feature's unused Connect Analytics CTA component

## Feature Description

As discussed here, https://github.com/google/site-kit-wp/issues/9442#issuecomment-2389387757, we are no longer using the Connect Analytics CTA component.

This needs to be finalised but the likelihood is we'll be removing it from the codebase. Once we've discussed this and assuming it's been confirmed, we can move this issue to IB and close #9442.

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_Do not alter or remove anything below. The following sections will be managed by moderators only._

## Acceptance criteria

* The Audience Segmentation feature's [Connect Analytics CTA component](https://google.github.io/site-kit-wp/storybook/develop/?path=/story/modules-analytics4-components-audiencesegmentation-dashboard-connectanalyticsctawidget--default) should be removed from the codebase.

## Implementation Brief

- [ ] Remove export of the component from `assets/js/modules/analytics-4/components/audience-segmentation/dashboard/index.js`

- [ ] In `assets/js/modules/analytics-4/index.js`
- Remove `widgets.registerWidget` [call](https://github.com/google/site-kit-wp/blob/d14b485de256601a435b667fe25b3f22a1d37c06/assets/js/modules/analytics-4/index.js#L232-L257) for the `ConnectAnalyticsCTAWidget` component.

- [ ] Delete `assets/js/modules/analytics-4/components/audience-segmentation/dashboard/ConnectAnalyticsCTAWidget.js` and `assets/js/modules/analytics-4/components/audience-segmentation/dashboard/ConnectAnalyticsCTAWidget.stories.js`

### Test Coverage

- Remove any stories and tests associated with the component.

## QA Brief

*

## Changelog entry

*