Stealthburner printhead for TZ-E3v2 Hot end

Accidently mis-labeled by afterburner head, and had requests for a stealthburner.

Untested as hotend is installed in my afterburner - but has ~1mm clearance requires the V6 collar to be fitted.

Nozzle should sit ~3mm below airduct

Voron stepfile had 2 back plates, so modified them both

Added clearance to the V6 stealthburner printhead