Apply multiple docker image tags when publishing images

[skuzzle]

As of #19698 spring boot has native support for building docker images which is a great approach to further simplify the build process.

When publishing docker images a common approach is to provide multiple tags per image. Probably most common is to publish the actual version along with an additional latest tag. I'd love to see Spring Boot support multiple tags per image (that would also simplify migrating from the also great jib plugin which already supports multiple tags)

[scottfrederick]

This is a good idea. As you can see in #19698, we haven't yet gotten to publishing generated docker images to a repository via the Spring Boot build tool plugins. This is a lower-priority feature as there are plenty of ways to do this with other tools like docker CLI, and publishing images from the Spring Boot build tool plugins might not make it into 2.3.0.RELEASE. I'll tag this as a useful feature of publishing if/when we do get to it.

[philwebb]

Blocked on #21001