Build fails on systems with Python 3.11 or later

[dragon0]

On systems with Python version 3.11 or later, WAF builds fail with the error ValueError: invalid mode: 'rUb'. This is because the 'U' file mode has been removed in Python 3.11. WAF has fixed this issue in version 2.1.2. Please bump waf to version 2.1.2.

[okaram]

I forked this repo to fix this issue. Feel free to use https://github.com/okaram/termbox-ok