[hail.fs] make rmtree retry transient errors (#10935)
[hail.fs] make rmtree retry transient errors (#10935)

While working on Hail Query on Hail Batch, I frequently encountered transient
errors in rmtree when cleaning up temporary cloud directories. This change
ensures rmtree is resilient to such failures.
hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail