Fix flaky ParallelScanIntegrationTest by adding pagination to scan requests

[S-Saranya1]

Motivation and Context

ParallelScanIntegrationTest.testParallelScan flakes in preview builds with small count mismatches (off by 1–5 items) at the assertion comparing single-segment scan results against 10-segment parallel scan results. 16 failures in the last 14 days. The root cause is that neither scan paginates - DynamoDB scan returns at most 1MB per call, and on the shared CI table with accumulated data, responses get truncated at different boundaries for the single-segment and multi-segment scans, producing different filtered counts.

Modifications

Replaced single-call dynamo.scan() with dynamo.scanPaginator() for both the single-segment scan and each of the 10 parallel segment scans, so all pages are read automatically before comparing counts. Also extracted the shared scan filter to reduce duplication.

Testing

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

[github-actions]

This pull request has been closed and the conversation has been locked. Comments on closed PRs are hard for our team to see. If you need more assistance, please open a new issue that references this one.