Investigate whether HOME env var is needed on manifest actions

[cliffano]

All actions (e.g. export backup) currently sets HOME to /root, but it's not clear whether it's really needed, and whether it needs to be that location. Ideally it shouldn't.

This is also the case at the next layer at aem_curator.

If this is proven to be not needed (via build pipeline test run), then let's take it off.