It should go outside of any VirtualHost directives. See:
Per definitions at:
and linked from context label for the entry, the value 'server config' means:
"""This means that the directive may be used in the server configuration files (e.g., httpd.conf), but not within any or containers. It is not allowed in .htaccess files at all."""
More importantly, do you really need to set it?
There are only certain times you would want to use WSGIPythonHome. Often people try and use it for the wrong reasons.