Use version-specific Docker images

[roncli]

Currently the latest version is used, version-specific should be used instead.

[roncli]

There is a known issue dependabot/dependabot-core#2247 where you cannot upgrade to the latest node LTS because dependabot doesn't know the difference between an LTS version and a normal version. This possibly could be resolved by https://github.com/nodejs/docker-node doing specific version LTS tags, ie: 16.17.0-lts-alpine. However, I'm going to work around it by ignoring versions higher than 16.x for now.