Add retry tests and onError cancel fix for presigned URL multipart downloads

[jencymaryjoseph]

Motivation and Context

1. PR 6320 fixed a bug in MultipartDownloaderSubscriber where in-flight GetObject futures were not cancelled when onError() was invoked. The presigned URL serial subscriber PresignedUrlMultipartDownloaderSubscriber had the same gap — when the publisher signals onError, the active HTTP request continues running until timeout instead of being cancelled immediately.

2. Also, added tests verifying retry behavior for presigned URL multipart downloads (retryable errors retry, non-retryable errors fail immediately).

Modifications

PresignedUrlMultipartDownloaderSubscriber.java — Track the current in-flight request and cancel it in onError() for immediate resource cleanup.

Testing

New file: PresignedUrlMultipartDownloaderSubscriberRetryWiremockTest.java — 9 parameterized tests × 2 transformer types (toBytes + toFile) = 18 runs covering non-retryable errors, retryable errors exhausting retries, IO errors, retry-then-succeed, and URL expiry during retry.

Screenshots (if appropriate)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Checklist

• I have read the CONTRIBUTING document
• Local run of mvn install succeeds
• My code follows the code style of this project
• My change requires a change to the Javadoc documentation
• I have updated the Javadoc documentation accordingly
• I have added tests to cover my changes
• All new and existing tests passed
• I have added a changelog entry. Adding a new entry must be accomplished by running the scripts/new-change script and following the instructions. Commit the new file created by the script in .changes/next-release with your changes.
• My change is to implement 1.11 parity feature and I have updated LaunchChangelog

License

• I confirm that this pull request can be released under the Apache 2 license

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