Read env vars in TestScheduler::many (#38897)

This allows ITERATIONS and SEED environment variables to override the
hard coded values during testing.

cc @ConradIrwin @as-cii 

Release Notes:

- N/A

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Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>
ae036f8eadNathan Sobo committed on 9/25/2025, 7:03:56 PM· committed by GitHubparentde1de25
2 files changedLine totals unavailable