Provide macos-sequoia-xcode:16 image (and other versions)

[Ribesg]

As described in this comment, the macos-runner image does not match the usage of some users. It consumes more than twice more data (both in networking and disk space) without any benefit to people just wanting to build one project with one xcode version on one macos version. In some cases, it's actually not usable at all due to disk space constraints.

We expected a macos-sequoia-xcode:16 image a month ago, as described in the README.md of this project:

Release Cadence

Once a new version of Xcode is released, we will initiate a GitHub release which will automatically build and push a new version of the macos-{sequoia,sonoma}-xcode:N image as well as macos-runner:sonoma. This generally happens within 24 hours of a release. Please watch this repository releases to get notified about new images.

It would be nice to know if this statement was actually not a goal, and if we're supposed to count on future updates too.