fix nbval command

Author: tylerhutcherson

.github/workflows/run_tests.yml

@@ -98,4 +98,4 @@ jobs:
         AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
         AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
       run: |
-        cd docs/ && pytest --nbval-lax --disable-warnings
+        cd docs/ && poetry run pytest --nbval-lax --disable-warnings