Generating tags for multiple bake targets

Description

Let's say I have the following docker-bake.hcl:

group "default" {
  targets = ["foo", "bar"]
}

target "foo" {
  dockerfile = "Dockerfile.foo"
  tags = ["my/foo:latest"]
}

target "bar" {
  dockerfile = "Dockerfile.bar"
  tags = ["my/bar:latest"]
}

The tags listed above function a bit like defaults, i.e., they're used when I run bake locally for testing. On GitHub Actions, however, I'd like to use docker/metadata-action to generate a list of tags based on various criteria (semver, date, etc...). These generated tags should replace the :latest tag from docker-bake.hcl, but I still want to keep the base name of the two images (my/foo and my/bar).

This would be trivial to accomplish with a single target (using the images input), but I didn't find a way to do it for multiple targets, where each target has a distinct image name.

Apologies if I missed something obvious (seems odd that this use case isn't already supported, since the whole point of bake is orchestrating the build of multiple targets).

Start by tracing the action's documented images input and its GitHub Actions integration with Docker Bake. Confirm how metadata-generated tags should replace :latest while preserving the distinct my/foo and my/bar base names, then add coverage for a group containing multiple targets.