DO NOT MERGE: build: use pipefail to not shadow command errors

As we use a function after the commands to format the output, if the first command of the pipe (ex. apt) fails, the second will not, and bash will consider the pipeline successful, not failing the script.

Bug: T348746 Signed-off-by: David Caro me@dcaro.es

This is just to track upstream https://github.com/fagiani/apt-buildpack/pull/24/files, once upstream is merged, we'll update the main branch here.