File docs_python.patch of Package gnatcoll-core

--- docs/generate_reference_guides.orig	2025-11-28 14:36:47.000000000 +0200
+++ docs/generate_reference_guides	2025-12-04 16:16:30.480792834 +0200
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 import os
 import re
 import shutil