Bump jupyter-server from 1.10.2 to 1.15.4

Bumps [jupyter-server](https://github.com/jupyter-server/jupyter_server) from 1.10.2 to 1.15.4.
- [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@v1.10.2...v1.15.4)

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

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

Author: dependabot[bot]

requirements.txt

@@ -48,7 +48,7 @@ jsonschema==3.2.0
 jupyter-cache==0.4.3
 jupyter-client==6.1.12
 jupyter-core==4.9.2
-jupyter-server==1.10.2
+jupyter-server==1.15.4
 jupyter-server-mathjax==0.2.3
 jupyter-sphinx==0.3.2
 jupyterlab-widgets==1.0.0