Support "fat-manifest" multi-arch container images

[anthr76]

🚀 Feature Request

Images like gcr.io/prysmaticlabs/prysm/validator:stable should support arm64

Description

These images should be able to be ran on amd64 or arm64

Describe the solution you'd like

The build system should implment a fat-manifest

Describe alternatives you've considered

Building, and maintaing my own image. This is required for multi-arch clusters without tolerating to amd64 which increases power usage.

[prestonvanloon]

Probably depends on bazelbuild/rules_docker#1599 or doing something else entirely.

[prestonvanloon]

Seems like we can do a workaround like this: buchgr/bazel-remote#453

[anthr76]

That looks like a suitable workaround. Are maintainers okay with something like that?

[prestonvanloon]

Fixed in #12428. We are planning to switch to these multi-arch images, starting in the next release.