Merge pull request #683 from bashtage/snyk-fix-2c6cb3f5c5d5d8b6e9eda25c3dc6c5c5

[Snyk] Fix for 4 vulnerabilities

Author: bashtage

requirements-dev.txt

@@ -43,3 +43,5 @@ sphinxcontrib-spelling
 sphinx_autodoc_typehints
 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
+fonttools>=4.61.0 # not directly required, pinned by Snyk to avoid a vulnerability
+tornado>=6.5.3 # not directly required, pinned by Snyk to avoid a vulnerability