fix: ga4 events

[adekbadek]

All Submissions:

• [x] Have you followed the Newspack Contributing guideline?
• [x] Does your code follow the WordPress' coding standards and VIP Go coding standards?
• [x] Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Changes proposed in this Pull Request:

Fixes above-header GA4 event handling.

Also simplifies the element selectors – @dkoo or @leogermani I'd be grateful for a review here since you were involved with the original implementation (https://github.com/Automattic/newspack-popups/pull/1136).

How to test the changes in this Pull Request:

1. On trunk, create a new above-header prompt. Insert a link (make it at #hash link for convenience)
2. Create an inline prompt, also with a link
3. Ensure you have GA4 configured via Site Kit
4. Use an extension or simply monitor collect requests in the network tab
5. Click the links in both prompts, observe that only the inline one triggers a GA4 event to be sent
6. Switch to this branch, observe that both prompts trigger a GA4 event when then link within is clicked

Other information:

• [x] Have you added an explanation of what your changes do and why you'd like us to include them?
• [ ] Have you written new tests for your changes, as applicable?
• [x] Have you successfully ran tests with your changes locally?

[matticbot]

:tada: This PR is included in version 2.31.1-alpha.1 :tada:

The release is available on GitHub release

Your semantic-release bot :package::rocket:

[matticbot]

:tada: This PR is included in version 2.31.1 :tada:

The release is available on GitHub release

Your semantic-release bot :package::rocket: