🧪 scripts: Add unit tests for dl_cleanup parseVer_1234

[ManupaKDU]

🎯 What: The testing gap addressed is the lack of unit test coverage for the parseVer_1234 parsing function in scripts/dl_cleanup.py.
📊 Coverage: Scenarios now tested include standard extraction with hyphens, extraction with underscores, ValueError gracefully failing on non-integer segments, and IndexError gracefully failing on malformed match objects.
✨ Result: Test coverage improved, ensuring reliable behavior of parseVer_1234 for current and future parsing logic refactors.

Signed-off-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>

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PR created automatically by Jules for task 5932635230009644662 started by @manupawickramasinghe

[google-labs-jules]

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