Bump notebook from 5.7.0 to 6.1.5 in /PaddleRec/ncf (#4961)

Bumps [notebook](https://github.com/jupyter/jupyterhub) from 5.7.0 to 6.1.5.
- [Release notes](https://github.com/jupyter/jupyterhub/releases)
- [Changelog](https://github.com/jupyterhub/jupyterhub/blob/master/CHECKLIST-Release.md)
- [Commits](https://github.com/jupyter/jupyterhub/commits)
Signed-off-by: Ndependabot[bot] <support@github.com>
Co-authored-by: Ndependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

PaddleRec/ncf/requirements.txt

@@ -59,7 +59,7 @@ nbformat==4.4.0
 networkx==2.4
 nltk==3.4.5
 nodeenv==1.3.4
-notebook==5.7.0
+notebook==6.1.5
 numba==0.48.0
 numpy==1.16.4
 oauthlib==3.1.0