Merge pull request #853 from bashtage/snyk-fix-d7bd223d22ac8c1c11201c0d16fcd2aa

[Snyk] Fix for 3 vulnerabilities

Author: bashtage

requirements-dev.txt

@@ -42,3 +42,5 @@ sphinx-autodoc-typehints
 pickleshare
 jupyterlab>=4.4.8 # not directly required, pinned by Snyk to avoid a vulnerability
 zipp>=3.19.1 # not directly required, pinned by Snyk to avoid a vulnerability
+jupyter-server>=2.20.0 # not directly required, pinned by Snyk to avoid a vulnerability
+tornado>=6.5.7 # not directly required, pinned by Snyk to avoid a vulnerability