Keep GHDL release versions on the Docker Hub

[maleiter]

It would be great if the release versions of GHDL remain on the DockerHub.

So the user can decide to use the latest release instead of the latest nightly build.

[Paebbels]

Hi.

Is there any interest in special docker images or just the plain ghdl + bookworm? The nightly tag pushes now directly to Docker Hub and we're discussing if and what should be maintained from that repository.

---

/cc @tgingold