fix: correct sagemaker methods over deprecated ones after Sagemaker SDK V2 update

[adelmofilho]

Sagemaker SDK V2 had made several changes and made the notebook named Tutorials/Boston Housing - XGBoost (Batch Transform) - High Level.ipynb went on an error when trying to get the xgboost container image. I have made adjustments on the proper code lines.

[gmariotti]

Hey @adelmofilho, I'm going through the course too, and pretty much all the notebooks in Tutorials need to be updated. Does it make sense to do it in this PR?

[adelmofilho]

I agree @gmariotti. I'm going to update this PR with adapted notebooks to Sagemaker SDK V2. I could also see variable names are repeated over many cells with different purporses.

Another possible update would be allow the code to be executed outside a Sagemaker Notebook in case you want to run the training jobs on your personal account but without the need to pay for Sagemaker Notebooks.

Please feel free to contribute as well!