does not work for python > 3.9 - fix included

[nicman23]

need to change line

shofel2/exploit/shofel2.py

Line 220 in e9dd9a4

 data = s.ep1_read(4096).tostring() 

from toString -> toBytes

relevant fix a different project (i tested and it booted mainline 5.0).

https://github.com/python-intelhex/intelhex/pull/46/files

[shuffle2]

thanks, you can try 16e2e9c to see if it's working. (I haven't actually tested locally 🙃)