Flaky `test_chaos_rechunk` due to windows disk errors

[fjetter]

We see a couple of flaky failures of test_chaos_rechunk due to flaky Windows disks.

I suggest to mark this test skip on windows iff #6628 did not resolve this issue.

Relates to #6639

No failures on osx and ubuntu. It appears #6535 might not be an issue any more

[fjetter]

Seems to be fixed

First commit without any failures was after merging #6651