Enable shared Azure and OneLake test resources for maintainers

@crepererum and I were talking the other day and it might be a good idea to get access to a real azure bucket to test against -- perhaps @kevinjqliu could help facilitate this somehow (I am not sure the best way to integrate real integration tests)

_Originally posted by @alamb in https://github.com/apache/arrow-rs-object-store/pull/711#discussion_r3398883883_

### Context
Disclosure: I am a Microsoft employee and currently work on Microsoft OneLake, our SaaS data lake offering.

I’m happy to help provide real Azure buckets and OneLake accounts for testing against production services. This repo is important to us in Azure Storage and Azure Data, and we want to help ensure compatibility and alignment with the open source ecosystem.

There may also be a possibility of sponsorship through Microsoft Open Source.

I’d love to hear thoughts on the best way to proceed. I can provision accounts and share access with maintainers. I’m also happy to move the conversation to the dev list if that would be better.

No files or tests are named. Start by reviewing the discussion linked from pull request 711 and the repository's existing Azure integration-test approach, then determine how maintainers could securely use shared Azure buckets and OneLake accounts. Done means an agreed integration path and accessible test resources for maintainers.

Written by the indexing model from the issue text.