Fix type inference scope for uploaded datasets

[Irozuku]

Summary

Fixes a minor indentation issue in the run method to ensure the dataset type inference logic is applied only to datasets uploaded via the Datasets tab and not to those created from notebooks.

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Type of Change

Check all that apply like this [x]:

• Backend change
• Frontend change
• CI / Workflow change
• Build / Packaging change
• Bug fix
• Documentation

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Changes (by file)

• DashAI/back/job/dataset_job.py:
  Corrected the indentation in the run method so type inference is executed only for datasets uploaded from the Datasets tab.

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Testing

• Uploaded a dataset via the Datasets tab and verified type inference still runs.
• Created a dataset from a notebook and confirmed type inference is not triggered.