Release Object Store 0.9.1

[tustvold]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.

It has been almost 2 months since the last object_store release and there have been a few tweaks and fixes since then - https://github.com/apache/arrow-rs/pulls?q=is%3Apr+is%3Aclosed+label%3Aobject-store.

Additionally there are breaking changes in the pipeline #5334 and it would be good to cut a patch release before the next breaking release.

Describe the solution you'd like

I intend to cut the release this week, once #5431 has been merged.

Describe alternatives you've considered

Additional context

FYI @wjones127 @roeap

[tustvold]

label_issue.py automatically added labels {'object-store'} from #5449