[AutoDiff upstream] set EnableExperimentalDifferentiableProgramming bool (#28001)
[AutoDiff upstream] set EnableExperimentalDifferentiableProgramming bool (#28001)

I noticed that the PR introducing `EnableExperimentalDifferentiableProgramming` (https://github.com/apple/swift/pull/27446) does not actually set it. This PR sets it.
roambotics/swift,ahoppen/swift,tkremenek/swift,atrick/swift,hooman/swift,harlanhaskins/swift,karwa/swift,stephentyrone/swift,glessard/swift,aschwaighofer/swift,benlangmuir/swift,gregomni/swift,karwa/swift,hooman/swift,nathawes/swift,atrick/swift,gregomni/swift,aschwaighofer/swift,apple/swift,xwu/swift,tkremenek/swift,lorentey/swift,aschwaighofer/swift,JGiola/swift,allevato/swift,jckarter/swift,gribozavr/swift,ahoppen/swift,lorentey/swift,allevato/swift,gribozavr/swift,stephentyrone/swift,CodaFi/swift,karwa/swift,CodaFi/swift,roambotics/swift,rudkx/swift,airspeedswift/swift,ahoppen/swift,tkremenek/swift,glessard/swift,harlanhaskins/swift,parkera/swift,aschwaighofer/swift,stephentyrone/swift,nathawes/swift,airspeedswift/swift,jckarter/swift,nathawes/swift,gregomni/swift,CodaFi/swift,jckarter/swift,hooman/swift,glessard/swift,tkremenek/swift,gribozavr/swift,jmgc/swift,lorentey/swift,atrick/swift,parkera/swift,benlangmuir/swift,gribozavr/swift,harlanhaskins/swift,gribozavr/swift,rudkx/swift,aschwaighofer/swift,benlangmuir/swift,atrick/swift,ahoppen/swift,nathawes/swift,lorentey/swift,tkremenek/swift,JGiola/swift,parkera/swift,stephentyrone/swift,rudkx/swift,harlanhaskins/swift,glessard/swift,hooman/swift,gregomni/swift,atrick/swift,harlanhaskins/swift,glessard/swift,aschwaighofer/swift,jckarter/swift,gribozavr/swift,roambotics/swift,hooman/swift,roambotics/swift,rudkx/swift,karwa/swift,allevato/swift,glessard/swift,CodaFi/swift,xwu/swift,allevato/swift,harlanhaskins/swift,harlanhaskins/swift,apple/swift,JGiola/swift,jmgc/swift,lorentey/swift,apple/swift,atrick/swift,parkera/swift,benlangmuir/swift,gribozavr/swift,nathawes/swift,jckarter/swift,airspeedswift/swift,roambotics/swift,parkera/swift,CodaFi/swift,airspeedswift/swift,allevato/swift,apple/swift,parkera/swift,rudkx/swift,benlangmuir/swift,JGiola/swift,stephentyrone/swift,ahoppen/swift,tkremenek/swift,allevato/swift,roambotics/swift,xwu/swift,tkremenek/swift,aschwaighofer/swift,stephentyrone/swift,lorentey/swift,jmgc/swift,gribozavr/swift,xwu/swift,nathawes/swift,parkera/swift,jckarter/swift,apple/swift,JGiola/swift,airspeedswift/swift,xwu/swift,jckarter/swift,nathawes/swift,karwa/swift,hooman/swift,benlangmuir/swift,CodaFi/swift,xwu/swift,ahoppen/swift,xwu/swift,jmgc/swift,gregomni/swift,jmgc/swift,lorentey/swift,karwa/swift,gregomni/swift,hooman/swift,jmgc/swift,lorentey/swift,karwa/swift,rudkx/swift,airspeedswift/swift,apple/swift,airspeedswift/swift,CodaFi/swift,JGiola/swift,jmgc/swift,karwa/swift,stephentyrone/swift,parkera/swift,allevato/swift