🧹 Fix unused imports in references/script_4.py

[manupawickramasinghe]

🎯 What: Removed unused imports (math, json, collections.OrderedDict, and elements of typing) in references/script_4.py.
💡 Why: Reduces namespace pollution, removes linting errors, and slightly speeds up module initialization.
✅ Verification: Verified via flake8 checks (unused import warnings resolved) and full successful test runs of both the script directly and the wider python tests.
✨ Result: Improved codebase maintainability without changing runtime behavior.

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PR created automatically by Jules for task 15858610067151356189 started by @manupawickramasinghe

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