Fix repeated backgrounds with transparent images

[ajlende]

Description

See #28310 (comment)

cover-srcset-repeated.mp4

In re-enabling the image repeat feature, I missed removing the <img> element when it was enabled. This removes that <img> element when the repeat feature is enabled. Thanks again to @stokesman!

How has this been tested?

Easiest to see with an image using transparency or a small image, enable the repeat feature and see that there isn't an overlapping image with the background.

Screenshots

Types of changes

Bug fix.

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR.

[mkaz]

I didn't test previously with an image that had transparency, so missed this previous.
It looks fine now, tested with small transparent image and don't notice the same.