ci: use docker github builder to build bin image and binaries

[crazy-max]

docker/github-builder#21
closes #3005
closes #3441

[crazy-max]

Can't use env with reusable workflows 😞

https://github.com/docker/buildx/actions/runs/19329818722

Seems we need an extra job just to set it as an output: https://github.com/orgs/community/discussions/26671 😑

🙃 https://github.com/orgs/community/discussions/26671#discussioncomment-4295807

[crazy-max]

GitHub hosted runner doesn't have enough space to build our image: https://github.com/docker/buildx/actions/runs/19330419315/job/55292703625#step:8:521

#28 [linux/amd64->darwin/amd64 buildx-build 1/1] RUN --mount=type=bind,target=.   --mount=type=cache,target=/root/.cache   --mount=type=cache,target=/go/pkg/mod   --mount=type=bind,from=buildx-version,source=/buildx-version,target=/buildx-version <<EOT (set -e...)
#28 1051.0 k8s.io/api/autoscaling/v2beta1: mkdir /tmp/go-build135885827/b986/: no space left on device

Hence why we free up disk space currently (see #3040)

For our reusable workflow, one way to fix it would be to distribute build across runners: docker/github-builder#2

[crazy-max]

Switch reusable workflow ref to bake-distrib docker/github-builder#22 so builds are distributed across runners.

[crazy-max]

Pushed extra commit to also build our binaries with our reusable workflow.

[dvdksn]

This one shouldn't be here right?

Suggested change

push: ${{ github.event_name != 'pull_request' }}

[dvdksn]

Oh I see:

https://github.com/docker/github-builder-experimental/blob/36714dbaf49f1f3518cd865748c85b863cdbcbe4/.github/workflows/bake.yml#L36C69-L36C117

Something like sign-artifacts: ${{ github.event_name != 'pull_request' }} might be more intuitive, splitting push and manifest signing for local artifacts.

[crazy-max]

Yes I'm working on refactoring the UX, I don't really like push as well, that's misleading. I will open an issue on github-builder repo to address this 🙏