Merged test and notebook workflows into one, removed old separate workflow files

[Ahmed-Tahan7]

Hello

I combined test-workflow and notebook-workflow into one and deleted old files.

Here is what my code does:

• Runs tests using pytest
• Builds the Jupyter Book if conditions are met (develop branch push)
• Deploys to DCE-DSC-MRI_TestResults if successful

Let me know if any changes or cleanup are needed