maintain support for amd64 architecture

[sjpalf]

The latest mozilla/sbt images on docker hub have been built using linux/arm64/v8 architecture. These images no longer work on linux/amd64, with the error:

standard_init_linux.go:228: exec user process caused: exec format error

Could these images be built and pushed to docker hub using buildx to support both linux/amd64 & linux/arm64/v8?

[steve-e]

👍

[jklukas]

I'd be open to a PR that updates the deployment instructions in the README to use buildx and then I'll use that command going forward.

[davidzajac1]

Trying to build this image within a GitHub runner and keep getting The requested image's platform (linux/arm64/v8) does not match the detected host platform (linux/amd64) and no specific platform was requested. Tried using docker buildx and a variety of other strategies. I think adding an image for amd64 would fix this.