Possible fix for multi-arch build failures

[llinder]

Enables buildx in an attempt to resolve issue #14

[codefromthecrypt]

might be a good solution though I want to look carefully and understand why. Incidentally, the overlapping architecture problem was one motivation for disabling buildx!

[llinder]

Seems to be related to this pull request which I found while reading issue1170. The thread is fairly long and I don't full grasp the real issue here either. I check the manifest with docker manifest inspect ghcr.io/openzipkin/alpine:3.12.1 and arm64 exists. Seems like that PR now adds a warning that matches the exact message the build fails on invalid from flag value code: image with reference sha256:0804f89bf751879de277f04b8a2874502bbd4bceb12e7688394d9d64837bf7e7 was found but does not match the specified platform: wanted linux/arm64, actual: linux/amd64. Even though the comments say it's a Warning, the Docker build step seems to treat this as a hard failure. I will keep reading, maybe there is a way to ignore the warning in the build step but so far the only thing that I can get to work locally is to use buildx.

[codefromthecrypt]

🤞