Remove RTL banner versions.

[peterwilsoncc]

Describe the bug

The plugin repo asset guidelines note that right-to-left and language specific banners are only required if the banners differ from the English/left-to-right version.

This repo currently includes identical version of the banners for LTR and RTL languages, the latter can be removed.

Follow up to 4d6b5db

Steps to Reproduce

N/A

Screenshots, screen recording, code snippet

See https://github.com/10up/simple-podcasting/tree/cb64464eabd079ee80395ac7c50338072edaf1f3/.wordpress-org

Environment information

N/A

WordPress information

No response

Code of Conduct

• I agree to follow this project's Code of Conduct