Switch chainguard images to alternative Alpine-based images

[AlanGreene]

Changes

On July 15, 2024, Chainguard will be changing their base images to be based on their own custom Wolfi base. This means they will be dropping support for a number of platforms, keeping only linux/arm64 and linux/amd64.

Switch to their alternative Alpine-based images to maintain support for other platforms such as linux/s390x and linux/ppc64le.

See https://www.chainguard.dev/unchained/changes-to-static-git-and-busybox-developer-images-2 for more details.

/kind misc

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• [ ] Docs included if any changes are user facing
• [ ] Tests included if any functionality added or changed
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Release Notes

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