[docs] Fix Objective-C bridging attribute name. (#28495)
[docs] Fix Objective-C bridging attribute name. (#28495)

Correct attribute name is `objc_bridge_mutable` according to
https://github.com/llvm/llvm-project/blob/40963b2bf0e72626d21917a08f3c86e56541ae7a/clang/include/clang/Basic/Attr.td#L1743
JGiola/swift,airspeedswift/swift,aschwaighofer/swift,stephentyrone/swift,tkremenek/swift,CodaFi/swift,rudkx/swift,xwu/swift,tkremenek/swift,atrick/swift,ahoppen/swift,xwu/swift,benlangmuir/swift,ahoppen/swift,airspeedswift/swift,gregomni/swift,karwa/swift,tkremenek/swift,tkremenek/swift,rudkx/swift,nathawes/swift,harlanhaskins/swift,lorentey/swift,jmgc/swift,airspeedswift/swift,harlanhaskins/swift,hooman/swift,stephentyrone/swift,lorentey/swift,CodaFi/swift,aschwaighofer/swift,hooman/swift,hooman/swift,gregomni/swift,karwa/swift,jmgc/swift,benlangmuir/swift,stephentyrone/swift,aschwaighofer/swift,CodaFi/swift,apple/swift,glessard/swift,glessard/swift,hooman/swift,airspeedswift/swift,gribozavr/swift,gribozavr/swift,karwa/swift,stephentyrone/swift,JGiola/swift,aschwaighofer/swift,jckarter/swift,apple/swift,jckarter/swift,benlangmuir/swift,nathawes/swift,allevato/swift,glessard/swift,apple/swift,ahoppen/swift,karwa/swift,jckarter/swift,allevato/swift,rudkx/swift,lorentey/swift,allevato/swift,allevato/swift,atrick/swift,lorentey/swift,CodaFi/swift,allevato/swift,harlanhaskins/swift,roambotics/swift,airspeedswift/swift,jckarter/swift,roambotics/swift,ahoppen/swift,glessard/swift,benlangmuir/swift,xwu/swift,atrick/swift,atrick/swift,karwa/swift,hooman/swift,xwu/swift,gribozavr/swift,xwu/swift,nathawes/swift,gribozavr/swift,CodaFi/swift,gribozavr/swift,harlanhaskins/swift,rudkx/swift,lorentey/swift,hooman/swift,gribozavr/swift,apple/swift,stephentyrone/swift,roambotics/swift,atrick/swift,JGiola/swift,xwu/swift,ahoppen/swift,jckarter/swift,harlanhaskins/swift,gregomni/swift,harlanhaskins/swift,jmgc/swift,lorentey/swift,glessard/swift,CodaFi/swift,JGiola/swift,nathawes/swift,JGiola/swift,airspeedswift/swift,lorentey/swift,gregomni/swift,harlanhaskins/swift,hooman/swift,apple/swift,CodaFi/swift,aschwaighofer/swift,parkera/swift,karwa/swift,gregomni/swift,nathawes/swift,tkremenek/swift,atrick/swift,airspeedswift/swift,karwa/swift,roambotics/swift,tkremenek/swift,allevato/swift,nathawes/swift,aschwaighofer/swift,roambotics/swift,benlangmuir/swift,jmgc/swift,karwa/swift,roambotics/swift,JGiola/swift,parkera/swift,apple/swift,stephentyrone/swift,gribozavr/swift,parkera/swift,benlangmuir/swift,parkera/swift,parkera/swift,nathawes/swift,stephentyrone/swift,gregomni/swift,aschwaighofer/swift,tkremenek/swift,rudkx/swift,lorentey/swift,gribozavr/swift,xwu/swift,jmgc/swift,jmgc/swift,rudkx/swift,ahoppen/swift,parkera/swift,jckarter/swift,jmgc/swift,glessard/swift,allevato/swift,parkera/swift,parkera/swift,jckarter/swift