Use /usr/bin/env python3 instead of /usr/bin/python3 project-wide

config/apparmor/lxc-generate-aa-rules.py

-#!/usr/bin/python3
+#!/usr/bin/env python3
 
 import sys
 

src/lxc/lxc-ls.in

-#!/usr/bin/python3
+#!/usr/bin/env python3
 #
 # lxc-ls: List containers
 #

src/lxc/lxc-start-ephemeral.in

-#!/usr/bin/python3
+#!/usr/bin/env python3
 #
 # lxc-start-ephemeral: Start a copy of a container using an overlay
 #

src/python-lxc/examples/api_test.py

-#!/usr/bin/python3
+#!/usr/bin/env python3
 #
 # api_test.py: Test/demo of the python3-lxc API
 #

src/python-lxc/examples/pyconsole-vte.py

-#!/usr/bin/python3
+#!/usr/bin/env python3
 #
 # pyconsole-vte: Example program showing use of console functions
 #                in the lxc python binding

src/python-lxc/examples/pyconsole.py

-#!/usr/bin/python3
+#!/usr/bin/env python3
 #
 # pyconsole: Example program showing use of console functions
 #            in the lxc python binding

src/python-lxc/setup.py.in

-#!/usr/bin/python3
+#!/usr/bin/env python3
 #
 # python-lxc: Python bindings for LXC
 #