Clarify Python version required is 3.12

Author: gezalore

README.rst

@@ -34,7 +34,7 @@ Dependencies
 We try to keep external dependencies to a minimum. You will need the following
 available through your shell ``$PATH``:
 
-- Python 3.9 or newer as ``python3``
+- Python 3.12 or newer as ``python3``
 - An installation of Verilator as ``verilator``
 
 All other dependencies are managed via a Python virtual environment, please see

docs/source/gettingstarted.rst

@@ -19,7 +19,7 @@ Start by cloning the repository, then ``cd`` to the root of the project:
 Setting up dependencies
 -----------------------
 
-We assume you have Python 3.9 or newer available through your shell ``$PATH``
+We assume you have Python 3.12 or newer available through your shell ``$PATH``
 as ``python3``. To confirm, you can run ``python3 --version``.
 
 Python dependencies are manged through a virtual environment that you can