ENH: Enable notebook CI check

Enabled check to run example notebooks with Python wheels built as part
of CI validation. Adds `requirements.txt` file to inform package
management for running notebooks.

Author: tbirdso

.github/workflows/build-test-package.yml

@@ -8,5 +8,7 @@ jobs:
 
   python-build-workflow:
     uses: InsightSoftwareConsortium/ITKRemoteModuleBuildTestPackageAction/.github/workflows/build-test-package-python.yml@03626a23c22246e89e36c7e918a158c440f9b099
+    with:
+      test-notebooks: true
     secrets:
       pypi_password: ${{ secrets.pypi_password }}

requirements.txt

@@ -0,0 +1,5 @@
+itk>=v5.3.0
+itk-meshtopolydata>=0.10.0
+traitlets<5.7.0
+ipywidgets>=7.1.2
+itkwidgets