Build is including x86 libraries in the arm build

[stevendborrelli]

Bug Report

What happened?

For some reason the arm64 build is including x86 images in the build:

How can we reproduce it?

Run a recent build on an arm Mac system, for example. https://github.com/crossplane-contrib/function-shell/actions/runs/15601376815/job/43941818507

$ docker run  ghcr.io/crossplane-contrib/function-shell@sha256:36b7ccd7124c762f7ee377e213390f38b7323a676f4307ffd017eb2bd2fb7725 --insecure

Verify the architecture as arm64:

$ docker inspect ghcr.io/crossplane-contrib/function-shell@sha256:36b7ccd7124c762f7ee377e213390f38b7323a676f4307ffd017eb2bd2fb7725 | jq '.[0].Architecture'
"arm64"

Run the function image:

$ docker run  ghcr.io/crossplane-contrib/function-shell@sha256:36b7ccd7124c762f7ee377e213390f38b7323a676f4307ffd017eb2bd2fb7725 --insecure

Exec to a shell and examine the shell and other binaries, they will be x86.

$ file /usr/bin/dash
/usr/bin/dash: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=be6397ddffc3e384c505d7deab3bed190c884df9, for GNU/Linux 3.2.0, stripped

What environment did it happen in?

Function version:

[stevendborrelli]

Buildx seems to support arm:

https://github.com/crossplane-contrib/function-shell/actions/runs/15601376815/job/43941818507#step:3:216

"nodes": [
      {
        "name": "builder-31a22ea7-b26d-4cc6-9814-874438a9b2f50",
        "endpoint": "unix:///var/run/docker.sock",
        "status": "running",
        "buildkitd-flags": "--debug --allow-insecure-entitlement=network.host",
        "buildkit": "v0.22.0",
        "platforms": "linux/amd64,linux/amd64/v2,linux/amd64/v3,linux/arm64,linux/riscv64,linux/ppc64le,linux/s390x,linux/386,linux/mips64le,linux/mips64,linux/loong64,linux/arm/v7,linux/arm/v6",
        "features": {
          "Automatically load images to the Docker Engine image store": true,
          "Cache export": true,
          "Direct push": true,
          "Docker exporter": true,
          "Multi-platform build": true,
          "OCI exporter": true
        },

[stevendborrelli]

Testing PR #61

$ file usr/bin/dash
/usr/bin/dash: ELF 64-bit LSB pie executable, ARM aarch64, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-aarch64.so.1, BuildID[sha1]=203461ab74495108600eb023c46b7e8413529eea, for GNU/Linux 3.7.0, stripped

$ aws --version
aws-cli/2.27.34 Python/3.13.3 Linux/6.10.14-linuxkit exe/aarch64.debian.12

[stevendborrelli]

I'm waiting for more testing before cutting a new release using this build, but in my initial testing the correct binaries are included now.