Optimize Dockerfile to use `apk add` with `--no-cache`

[PeterDaveHello]

Make apk add to use --no-cache for package installation. This will prevent the package index from being cached and reduce the image size.

Checklist

Not all of these might apply to your change but the more you are able to check the easier it will be to get your contribution merged.

• [ ] CI passes
• [x] Description of proposed change
• [ ] Documentation (README, docs/, man pages) is updated
• [ ] Existing issue is referenced if there is one
• [ ] Unit tests for the proposed change