tutorial_pca.ipynb uses removed `sklearn.datasets.fetch_mldata`

[lancechua]

Describe the mistake

In sklearn v1.0.2, from sklearn.datasets import fetch_mldata raises an ImportError.

Location

• [ ] tutorials/tutorial_pca.ipynb, cell 1
• [ ] tutorials/tutorial_pca.solution.ipynb, cell 1

Proposed solution

Remove the import since it is not used anyway. The updated fetch_openml is already used in cell 2.

Additional context

sklearn.datasets.fetch_mldata was removed in sklearn v0.22 due to the website being inoperational.