Make TMP buckets less restricted

[MattWellie]

I'm not sure if this is the most appropriate place for this issue

I've recently noticed restrictions on -tmp buckets that cause unexpected workflow failures. One relates to Hail's way of staging files locally before copying to a remote bucket, then trying to delete the staged version as housekeeping (or at least this is my understanding, slack message)

Another relates to the presence of temp files for a pre-empted workflow. When the job repeats, writing to the existing path in tmp causes a workflow failure: see https://batch.hail.populationgenomics.org.au/batches/420291/jobs/1

Can we have the privileges reduced on -tmp sub-buckets so that they are writeable/over-writeable?