build-python: Bump to the latest version of cpython-mingw

This version fixes a race condition in the build, which in most
cases was benign but in rare cases could successfully build a Python
that would crash at runtime.

build-python.sh

@@ -18,7 +18,7 @@ set -e
 
 : ${LIBFFI_VERSION:=v3.4.4}
 : ${PYTHON_VERSION:=v3.11.6}
-: ${PYTHON_VERSION_MINGW:=9599c1cbffc8b1889f661b4da6463252e0722bed}
+: ${PYTHON_VERSION_MINGW:=03d9f3ca4807a327815ce80aceadc8154245e267}
 
 unset HOST