fix: Handle missing 'encryption' field in legacy dataset

[csy1204]

Before submitting

• Was this discussed/agreed via a Github issue? (no need for typos and docs improvements)
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• Did you make sure to update the docs?
• Did you write any new necessary tests?

What does this PR do?

• Adjusted the code to handle cases where the 'encryption' field is missing in the dataset, preventing errors from occurring.

Fixes #258

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[codecov]

Codecov Report

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Additional details and impacted files

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