scons: Use MacPorts' Python interpreter

Upstream-Status: Inappropriate [configuration]
Signed-off-by: Lawrence Velázquez <larryv@macports.org>

--- SCons/Utilities/ConfigureCache.py.orig	2020-12-20 23:00:17.000000000 -0600
+++ SCons/Utilities/ConfigureCache.py	2022-06-26 15:15:04.000000000 -0500
@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#!__PYTHON__
 #
 # SCons - a Software Constructor
 #
--- SCons/Utilities/sconsign.py.orig	2020-12-20 23:00:17.000000000 -0600
+++ SCons/Utilities/sconsign.py	2022-06-26 15:15:04.000000000 -0500
@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#!__PYTHON__
 #
 # SCons - a Software Constructor
 #