Open5GS and UERANSIM Docker images.

Images are built from upstream release tags rather than from the upstream default branch.

• latest - the most recent upstream release
• vX.Y.Z - a specific upstream release, e.g. v2.8.0

The pinned versions are the ARG OPEN5GS_VERSION and ARG UERANSIM_VERSION lines in each Dockerfile, so docker build ./open5gs reproduces the published image. The workflow bumps them when upstream publishes a new release.

https://docs.docker.com/compose/install/

docker compose pull
docker compose up -d
docker compose down