Finding out when a new docker image is available

[yanns]

In our build, we define the base image with a precise tag, like "eclipse-temurin:17.0.1_12-jdk-focal".
We still have to check whenever a new version is available.

Idea o new feature: adding a command that checks if a new docker image is available, like dependencyUpdates.
Maybe even integrating with dependencyUpdates or with https://github.com/scala-steward-org/scala-steward ?