Create or update an organization Actions secret

Encrypts and stores the value (at most 48 KiB) with its visibility. Names are case-insensitive and stored upper-cased: letters, digits and underscores, not starting with a digit or GITHUB_. Omitting visibility keeps the existing one's visibility and repositories (private for a new name). With visibility selected, omitting selectedRepositoryIds keeps the current list. Requires authenticated authority and enforces current resource policy.