Add setuptools/distutils to requirements

[randomir]

Since distutils and setuptools have been removed in python 3.12, and pandas_datareader (a requirement for this example) hasn't been updated in a while, so it still relies on distutils

...
  File "[..]/portfolio-optimization/env312/lib/python3.12/site-packages/pandas_datareader/compat/__init__.py", line 1, in <module>
    from distutils.version import LooseVersion

we should add setuptools (which still includes distutils) to requirements.txt.

We pre-install setuptools in orb-examples when running example tests, but outside of our CI, the requirements are not complete.