fix: requirements-demo.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-SETUPTOOLS-7448482

requirements-demo.txt

@@ -2,4 +2,4 @@ jupyterlab>=1.2.*
 matplotlib>=3.1.*
 quandl>=3.5.*
 pandas>=1.0.*
-setuptools>=65.5.1 # not directly required, pinned by Snyk to avoid a vulnerability
+setuptools>=70.0.0 # not directly required, pinned by Snyk to avoid a vulnerability