Currently the default bluez5 package installed is bluez-5.46, but we need this
locally for compiling bluez-5.41 (the stack using in the bluetooth
certification process), so we need to locally apply the same fix ("fix python3
core dependency for testtools") for the testtools and its dependency with
python3-code instead of python3.
Signed-off-by: Isaac Hermida <isaac.hermida@digi.com>