Chore: Add OpenSauced's GitHub Action pizza-action to the project

[nickytonline]

As a member of the OpenSauced organization, I want to add the OpenSauced's GitHub Action pizza-action to the project so that the app repository's CODEOWNERS file can stay up to date.

A part of this is removing https://github.com/open-sauced/landing-page/blob/main/.github/CODEOWNERS and letting the action create the new one as well as creating a .sauced.yaml file.