build: remove workaround for python fallback
build: remove workaround for python fallback

This forces the python3 interpreter to be found and no longer permits
the use of Python2 as a fallback if python3 is not found.

rudkx/swift,glessard/swift,gregomni/swift,hooman/swift,benlangmuir/swift,jmgc/swift,benlangmuir/swift,benlangmuir/swift,JGiola/swift,nathawes/swift,atrick/swift,airspeedswift/swift,JGiola/swift,hooman/swift,roambotics/swift,gregomni/swift,tkremenek/swift,ahoppen/swift,allevato/swift,ahoppen/swift,benlangmuir/swift,atrick/swift,glessard/swift,CodaFi/swift,jckarter/swift,roambotics/swift,CodaFi/swift,apple/swift,tkremenek/swift,airspeedswift/swift,parkera/swift,tkremenek/swift,JGiola/swift,gregomni/swift,JGiola/swift,rudkx/swift,airspeedswift/swift,CodaFi/swift,parkera/swift,allevato/swift,xwu/swift,CodaFi/swift,atrick/swift,apple/swift,parkera/swift,rudkx/swift,nathawes/swift,atrick/swift,rudkx/swift,hooman/swift,jckarter/swift,parkera/swift,glessard/swift,jckarter/swift,apple/swift,hooman/swift,nathawes/swift,xwu/swift,atrick/swift,tkremenek/swift,allevato/swift,airspeedswift/swift,hooman/swift,airspeedswift/swift,apple/swift,CodaFi/swift,airspeedswift/swift,jckarter/swift,jckarter/swift,CodaFi/swift,CodaFi/swift,jmgc/swift,JGiola/swift,parkera/swift,glessard/swift,ahoppen/swift,allevato/swift,apple/swift,jmgc/swift,xwu/swift,hooman/swift,gregomni/swift,ahoppen/swift,parkera/swift,airspeedswift/swift,gregomni/swift,benlangmuir/swift,roambotics/swift,xwu/swift,roambotics/swift,apple/swift,tkremenek/swift,allevato/swift,jmgc/swift,ahoppen/swift,roambotics/swift,allevato/swift,glessard/swift,hooman/swift,glessard/swift,allevato/swift,nathawes/swift,tkremenek/swift,jmgc/swift,nathawes/swift,parkera/swift,tkremenek/swift,ahoppen/swift,roambotics/swift,nathawes/swift,atrick/swift,jckarter/swift,jmgc/swift,jmgc/swift,xwu/swift,nathawes/swift,benlangmuir/swift,rudkx/swift,parkera/swift,xwu/swift,JGiola/swift,gregomni/swift,rudkx/swift,xwu/swift,jckarter/swift