Merge pull request #852 from bashtage/snyk-fix-d633e60aaa3d453676c1f415a883d732

[Snyk] Fix for 3 vulnerabilities

Author: bashtage

doc/requirements.txt

@@ -20,3 +20,5 @@ notebook
 sphinx-autodoc-typehints
 fonttools>=4.43.0 # not directly required, pinned by Snyk to avoid a vulnerability
 jupyterlab>=4.4.8 # 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