Bump jupyter-server from 2.18.0 to 2.20.0 in /notebook_python

Bumps [jupyter-server](https://github.com/jupyter-server/jupyter_server) from 2.18.0 to 2.20.0.
- [Release notes](https://github.com/jupyter-server/jupyter_server/releases)
- [Changelog](https://github.com/jupyter-server/jupyter_server/blob/main/CHANGELOG.md)
- [Commits](jupyter-server/jupyter_server@v2.18.0...v2.20.0)

---
updated-dependencies:
- dependency-name: jupyter-server
  dependency-version: 2.20.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

notebook_python/requirements_notebook.txt

@@ -37,7 +37,7 @@ jupyter-events==0.12.0
 jupyter-lsp==2.3.0
 jupyter_client==8.6.3
 jupyter_core==5.8.1
-jupyter_server==2.18.0
+jupyter_server==2.20.0
 jupyter_server_terminals==0.5.3
 jupyterlab==4.5.7
 jupyterlab_pygments==0.3.0