DL3019 info: Use the `--no-cache` switch to avoid the need to use `--update` and remove `/var/cache/apk/*` when done installing packages

SC2006 style: Use $(...) notation instead of legacy backticked `...`.

DL3019 info: Use the `--no-cache` switch to avoid the need to use `--update` and remove `/var/cache/apk/*` when done installing packages

DL3059 info: Multiple consecutive `RUN` instructions. Consider consolidation.

DL3059 info: Multiple consecutive `RUN` instructions. Consider consolidation.

DL3019 info: Use the `--no-cache` switch to avoid the need to use `--update` and remove `/var/cache/apk/*` when done installing packages