guf-image: Add python3 and pyserial to image
Create python3 packagegroup and add it to guf-image. Python3 was part of the image due to dependencies anyway but pyserial, used to test rts and cts is new.
BCS 746-000222
Create python3 packagegroup and add it to guf-image. Python3 was part of the image due to dependencies anyway but pyserial, used to test rts and cts is new.
BCS 746-000222