Docker multi platform image

[cometkim]

I have both Mac w/ OrbStack environment and an x64 Linux w/ Rancher Desktop environment, and I tried to configure a local test environment with a single docker-compose.yml file.

But it is a bit difficult ltbridge has multiple docker images by arch. It would be great if the image uses multi-platform build with the same tag.

[caibirdme]

Since I only have a linux(x86) machine and I only test ltbridge on linux x86. you can try to run ltbridge on linux x86 as well, and I'll try to add multi-platform-build

[cometkim]

I think the GitHub runner is already enough to build multi-platform images. If prebuilt binaries are included in the release (or actions artifact), Dockerfile requires simply ADD by TARGETOS and TARGETARCH. And the tags can be inherited from the base image as is. bookworm, alpine, etc.

I can file a draft PR if you'd like.

[caibirdme]

Good, any pr is appreciated

[cometkim]

Mixing Rust cross compilation with buildkit cross compilation makes it too complicated.

I think compiling using only buildx would make the configuration much simpler.