Apply ruff/pyupgrade rule UP010

UP010 Unnecessary `__future__` import for target Python version

Manually removed comments about Unicode literals.

Author: DimitriPapadopoulos

demo/btrfs-snap.py

@@ -3,8 +3,6 @@
 
 creates a exactly named snapshots and bails out if they exist
 """
-from __future__ import print_function
-
 import argparse
 import fcntl
 import os

demo/extern_python_varargs.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 import cffi
 
 ffi = cffi.FFI()

demo/fastcsv.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 import csv
 import cffi
 

demo/gmp.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 import sys
 #
 # This is only a demo based on the GMP library.

demo/manual2.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 import _cffi_backend
 
 ffi = _cffi_backend.FFI(b"manual2",

demo/pwuid.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 import sys, os
 
 # run pwuid_build first, then make sure the shared object is on sys.path

demo/pyobj.py

@@ -1,5 +1,3 @@
-from __future__ import print_function
-
 referents = []     # list "object descriptor -> python object"
 freelist = None
 

demo/readdir.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 # A Linux-only demo
 #
 import sys

demo/readdir2.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 # A Linux-only demo, using set_source() instead of hard-coding the exact layouts
 #
 import sys

demo/readdir_ctypes.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 # A Linux-only demo
 #
 # For comparison purposes, this is a ctypes version of readdir.py.