molten-vk: add HEAD support (#106277)
molten-vk: add HEAD support (#106277)

This involves moving some build steps to stable-only; I expect they'll
likely be removed altogether in some future stable version.
nbari/homebrew-core,stgraber/homebrew-core,makigumo/homebrew-core,chrisfinazzo/homebrew-core,filcab/homebrew-core,adam-moss/homebrew-core,filcab/homebrew-core,Homebrew/homebrew-core,sjackman/homebrew-core,nbari/homebrew-core,lemzwerg/homebrew-core,adam-moss/homebrew-core,makigumo/homebrew-core,stgraber/homebrew-core,Homebrew/homebrew-core,nandub/homebrew-core,nandub/homebrew-core,chrisfinazzo/homebrew-core,sjackman/homebrew-core,lemzwerg/homebrew-core