Bump workflow runner on release workflow

Signed-off-by: Jeff Mendoza <[email protected]>

build(deps): bump actions/upload-artifact from 4.4.3 to 4.5.0

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 4.4.3 to 4.5.0.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@b4b15b8...6f51ac0)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

go.mod: Update `go` directive to go1.12.12

Signed-off-by: Stephen Augustus <[email protected]>

Fix name of ko in cloudbuild

Signed-off-by: Jeff Mendoza <[email protected]>

Build chainguard/busybox based images for use with GitHub Actions

We would like the option of running AllStar as a GitHub Action. The current container image uses `cgr.dev/chainguard/static` which is an excellent minimal base with very little surface area. Unfortunately, GitHub Actions requires `tail` to be available for use as a container:

~~~sh
/usr/bin/docker create --name ... --label ... --workdir /__w/.allstar/.allstar --network ...  -e "HOME=/github/home" -e GITHUB_ACTIONS=true -e CI=true -v "/var/run/docker.sock":"/var/run/docker.sock" -v "/home/runner/work":"/__w" -v "/home/runner/runners/2.306.0/externals":"/__e":ro -v "/home/runner/work/_temp":"/__w/_temp" -v "/home/runner/work/_actions":"/__w/_actions" -v "/opt/hostedtoolcache":"/__t" -v "/home/runner/work/_temp/_github_home":"/github/home" -v "/home/runner/work/_temp/_github_workflo→
~~~

This change updates the build workflow to build a second image based on `cgr.dev/chainguard/busybox` with the tag `VERSION-busybox`.
Combining this image with use of the `-once` flag makes it possible to run AllStar in GitHub Actions.

Example GitHub Actions jobs YAML:
~~~
name: "Scheduled AllStar Enforcement"
on:
  schedule:
  - cron: "0 * * * *"

jobs:
  deployment:
    runs-on: ubuntu-latest
    container: ghcr.io/ossf/allstar:v3.1-busybox
    environment: prod
    steps:
      - name: "AllStar Enforce"
        env:
          APP_ID: ${{ vars.APP_ID }}
          KEY_SECRET: ${{ vars.KEY_SECRET }}
          PRIVATE_KEY: ${{ secrets.PRIVATE_KEY }}
        run: /ko-app/allstar -once
~~~

The standard minimal `cgr.dev/chainguard/stable` images are still built.

Signed-off-by: Paul Hirsch <[email protected]>

Fix Go version in release.yaml

Signed-off-by: Jeff Mendoza <[email protected]>

v2.0 Release