fix: remove "U" move from open(), now universal newline is the default

[sandrotosi]

In python2.7 you needed to specify mode='U' to get universal newline: https://docs.python.org/2.7/library/functions.html#open:~:text=universal%20newlines%20support%3B-,supplying%20%27U%27,-opens%20the%20file

in python3 this is now the default: https://docs.python.org/3/library/functions.html#open:~:text=if%20newline%20is%20None%2C%20universal%20newlines%20mode%20is%20enabled

but if left there, it now triggers an error with 3.11, so let's remove it

[CarliJoy]

@wolever can you merge this? Otherwise we will have troubles using the pkg with Python 3.11.

[thebaptiste]

@wolever can you merge this? Otherwise we will have troubles using the pkg with Python 3.11.

Yes, pprintpp doesn't work with python 3.11. Please merge and release !

[MatthewZMD]

ping @wolever