Remove the wp enqueue media in avatar default filter

[EHLOVader]

Description of the Change

Fixes conflict with plugins in which wp.media is not loaded or correctly working. Elementor page editor specifically fails to function due to this.

I see that this has been here for a long time, so I'm unsure what might have changed since then, but the Elementor image editor fails to work, doing wp_enqueue_media here appears to be the cause. Although I see that wp_enqueue_media also checks if it has run, so it isn't about enqueuing things twice.

Within the discussions options page the media library works still, I believe the media api is enqueue elsewhere so it will be available here, without having to do it here while the default avatar options are updated.

Closes #217

How to test the Change

Attempting to edit any image prior to this change in Elementor page editor would do nothing.
As well as tell tale console errors about wp.media and the javascript API

After this change testing and media library opens for Elementor image elements.
Further testing the discussions option page, and the default avatar option for local simple avatars is present and working, media library opens up, and assigning an image loads it into the form.

Changelog Entry

Fixed - Address conflicts with other plugins and loading the media API

Checklist:

• I agree to follow this project's Code of Conduct.
• I have updated the documentation accordingly.

I couldn't get the cypress unit tests to run, but it shouldn't require any new tests or affect the tests I see that exist

• I have added tests to cover my change.
• All new and existing tests pass.

[dkotter]

This looks good to me and things test fine without this line of code, so I think we're good to remove this. Thanks!