Update WindowsBuild.md
Update WindowsBuild.md

The CI is switching to ICU 67 since there are fixes in the latter version of ICU that are needed.  This should be further improved in the future to possibly use the the unicode.org releases.
CodaFi/swift,xwu/swift,allevato/swift,ahoppen/swift,roambotics/swift,allevato/swift,atrick/swift,nathawes/swift,gregomni/swift,glessard/swift,CodaFi/swift,benlangmuir/swift,jmgc/swift,jmgc/swift,tkremenek/swift,gregomni/swift,jckarter/swift,JGiola/swift,apple/swift,benlangmuir/swift,roambotics/swift,xwu/swift,airspeedswift/swift,stephentyrone/swift,apple/swift,rudkx/swift,tkremenek/swift,hooman/swift,jckarter/swift,stephentyrone/swift,ahoppen/swift,roambotics/swift,hooman/swift,jckarter/swift,ahoppen/swift,gregomni/swift,airspeedswift/swift,benlangmuir/swift,atrick/swift,rudkx/swift,xwu/swift,allevato/swift,apple/swift,apple/swift,airspeedswift/swift,glessard/swift,airspeedswift/swift,rudkx/swift,roambotics/swift,parkera/swift,parkera/swift,stephentyrone/swift,parkera/swift,stephentyrone/swift,jckarter/swift,parkera/swift,gregomni/swift,xwu/swift,ahoppen/swift,stephentyrone/swift,airspeedswift/swift,jckarter/swift,parkera/swift,xwu/swift,ahoppen/swift,nathawes/swift,benlangmuir/swift,hooman/swift,roambotics/swift,jmgc/swift,hooman/swift,atrick/swift,parkera/swift,CodaFi/swift,jmgc/swift,JGiola/swift,airspeedswift/swift,CodaFi/swift,atrick/swift,allevato/swift,apple/swift,nathawes/swift,tkremenek/swift,jckarter/swift,CodaFi/swift,jmgc/swift,parkera/swift,rudkx/swift,roambotics/swift,nathawes/swift,stephentyrone/swift,JGiola/swift,glessard/swift,xwu/swift,JGiola/swift,tkremenek/swift,allevato/swift,JGiola/swift,ahoppen/swift,hooman/swift,gregomni/swift,JGiola/swift,rudkx/swift,atrick/swift,airspeedswift/swift,allevato/swift,nathawes/swift,parkera/swift,glessard/swift,tkremenek/swift,nathawes/swift,stephentyrone/swift,apple/swift,jmgc/swift,jckarter/swift,glessard/swift,CodaFi/swift,nathawes/swift,rudkx/swift,CodaFi/swift,xwu/swift,jmgc/swift,hooman/swift,allevato/swift,gregomni/swift,benlangmuir/swift,atrick/swift,tkremenek/swift,glessard/swift,tkremenek/swift,benlangmuir/swift,hooman/swift