pssh-box.py parsing is not compatible with python3

[allanlei]

System info

Operating System: Manjaro Linux
Shaka Packager Version: 2.6.1

Issue and steps to reproduce the problem

Extra steps to reproduce the problem?

1. python3 pssh-box.py --from-base64 AAAAJHBzc2gAAAAA7e+LqXnWSs6jyCfc1R0h7QAAAAQiAhI0
   • python 3.11

What is the expected result?

PSSH Box v0
  System ID: Widevine edef8ba9-79d6-4ace-a3c8-27dcd51d21ed
  PSSH Data (size: 4):
    Widevine Data:
      Content ID: 1234

What happens instead?

Traceback (most recent call last):
  File "/usr/bin/pssh-box.py", line 438, in <module>
    main(sys.argv[1:])
  File "/usr/bin/pssh-box.py", line 396, in main
    boxes.extend(_parse_boxes(ns.input))
  File "/usr/bin/pssh-box.py", line 243, in _parse_boxes
    size = reader.read_int(4)
  File "/usr/bin/pssh-box.py", line 69, in read_int
    ret |= (ord(data[i]) << (8 * (size - i - 1)))
TypeError: ord() expected string of length 1, but int found

Using python2 is ok