docs: update model_governance_graph.ipynb

[eltociear]

Description of changes:
extenstion -> extension
Testing done:

Merge Checklist

Put an x in the boxes that apply. You can also fill these out after creating the PR. If you're unsure about any of them, don't hesitate to ask. We're here to help! This is simply a reminder of what we are going to look for before merging your pull request.

• I have verified that my PR does not contain any new notebook/s which demonstrate a SageMaker functionality already showcased by another existing notebook in the repository.
• I have read the CONTRIBUTING doc and adhered to the example notebook best practices
• I have updated any necessary documentation, including READMEs
• I have tested my notebook(s) and ensured it runs end-to-end
• I have linted my notebook(s) and code using black-nb -l 100 {path}/{notebook-name}.ipynb

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[review-notebook-app]

Check out this pull request on 

See visual diffs & provide feedback on Jupyter Notebooks.

---

Powered by ReviewNB

[sagemaker-bot]

AWS CodeBuild CI Report

• CodeBuild project: SageMakerNotebooksProd-USWEST2-amazon-sagemaker-examples-pr
• Commit ID: 88245df
• Result: SUCCEEDED
• Build Logs (available for 30 days)

Powered by github-codebuild-logs, available on the AWS Serverless Application Repository

[sagemaker-bot]

AWS CodeBuild CI Report

• CodeBuild project: SageMakerNotebooksProd-USWEST2-sagemaker-examples-link-check
• Commit ID: 88245df
• Result: SUCCEEDED
• Build Logs (available for 30 days)

Powered by github-codebuild-logs, available on the AWS Serverless Application Repository

[sagemaker-bot]

AWS CodeBuild CI Report

• CodeBuild project: SageMakerNotebooksProd-USWEST2-sagemaker-examples-code-formatting
• Commit ID: 88245df
• Result: SUCCEEDED
• Build Logs (available for 30 days)

Powered by github-codebuild-logs, available on the AWS Serverless Application Repository