🔒 Fix unsafe CSV deserialization by removing engine="python"

[derrynknife]

🎯 What: The pd.read_csv functions in surpyval/datasets/__init__.py were using engine="python", which can be vulnerable to unsafe CSV deserialization.
⚠️ Risk: The "python" engine for Pandas read_csv has historically had vulnerabilities or performance issues compared to the default "c" engine. Using it for data loading can expose users to unsafe execution if malicious CSVs are loaded.
🛡️ Solution: Removed the engine="python" argument from all pd.read_csv calls in the dataset loading functions. The default "c" engine is safer, faster, and perfectly capable of handling these standard CSV datasets.

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PR created automatically by Jules for task 5198042484183905525 started by @derrynknife

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