Remove calls to `projects/{}/{}/releases` endpoints

[szokeasaurusrex]

Instead of calling the Projects Releases endpoints, we should call the Organization Releases endpoints, as these endpoints are more flexible and should support all of the functionality that the Projects Releases endpoints support, and more (because no one-to-one project-release relationship is needed)

Deprecating these calls first should not be necessary, as the Organization Releases endpoint has been introduced over nine years ago, and we will clearly document the supported self-hosted versions when we release

See #2833 for background investigation

[linear]

CLI-186

[szokeasaurusrex]

We should also probably remove the project field from UpdatedRelease struct, and check whether any other fields of that struct are no longer needed