Use include for Python section of docs setup

Author: davisagli

docs/contributing/documentation/setup-build.md

@@ -31,10 +31,8 @@ Installation of Plone 6 Documentation includes prerequisites and the repository
 
 ### Python
 
-Installing Python is beyond the scope of this documentation.
-However, it is recommended to use a Python version manager, {term}`pyenv` that allows you to install multiple versions of Python on your development environment without destroying your system's Python.
-Plone requires Python version {SUPPORTED_PYTHON_VERSIONS_PLONE60}.
-
+```{include} /_inc/_install-python-plone60.md
+```
 
 (setup-build-installation-gnu-make-label)=