support: utils: use python3 explicitly

Python 2 is EOL sice 2020 [1], it's still available on distros, but may not
be installed by default (as being replaced by python3).

Thus remove compatibility imports:
from __future__ import print_function
from __future__ import absolute_import

Tested with python3 -m py_compile.

[1] https://www.python.org/doc/sunset-python-2/

Signed-off-by: Petr Vorel <petr.vorel@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

utils/check-package

@@ -1,7 +1,6 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # See utils/checkpackagelib/readme.txt before editing this file.
 
-from __future__ import print_function
 import argparse
 import inspect
 import os

utils/genrandconfig

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # Copyright (C) 2014 by Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
 #
@@ -18,8 +18,6 @@
 
 # This script generates a random configuration for testing Buildroot.
 
-from __future__ import print_function
-
 import contextlib
 import csv
 import os

utils/get-developers

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import argparse
 import getdeveloperlib

utils/getdeveloperlib.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 from io import open
 import os
 import re

utils/size-stats-compare

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # Copyright (C) 2016 Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>