Error when duplicating virtual dataset

[yousoph]

Getting an error when trying to duplicate a virtual dataset (feature in this PR: #20309)

How to reproduce the bug

1. Visit the Datasets page
2. On the Actions column of a Virtual dataset, click the duplicate icon
3. Enter a dataset name and click "Duplicate"

Expected results

Virtual dataset gets copied and created successfully

Actual results

An error message appears and the dataset doesn't get created

Screenshots

Environment

(please complete the following information):

• browser type and version:
• superset version: master
• python version: python --version
• node.js version: node -v
• any feature flags active:

Checklist

Make sure to follow these steps before submitting your issue - thank you!

• I have checked the superset logs for python stacktraces and included it here as text if there are any.
• I have reproduced the issue with at least the latest released version of superset.
• I have checked the issue tracker for the same issue and I haven't found one similar.

[yousoph]

@reesercollins