build-sys: invoke scripts with $PYTHON during build

Python binary to be used during compilation can be set with
./configure PYTHON=...

The she-bang line is removed, since it is not used anymore.

Makefile.am

@@ -3307,8 +3307,8 @@ dist_pkgdata_DATA += \
 dist_noinst_SCRIPT = \
 	src/locale/generate-kbd-model-map
 
-update-kbd-model-map:
-	src/locale/generate-kbd-model-map > src/locale/kbd-model-map
+update-kbd-model-map: src/locale/generate-kbd-model-map
+	$PYTHON $< > src/locale/kbd-model-map
 
 localectl_SOURCES = \
 	src/locale/localectl.c

make-man-index.py

@@ -1,4 +1,3 @@
-#!/usr/bin/env python
 #  -*- Mode: python; indent-tabs-mode: nil -*- */
 #
 #  This file is part of systemd.

src/locale/generate-kbd-model-map

@@ -1,5 +1,3 @@
-#!/usr/bin/python
-
 import sys
 import system_config_keyboard.keyboard_models