Migrate DragDropRegistry to CDK 20
ProprietaryCDK 20 made DragDropRegistry non-generic and removed its scroll subject. Removes the type arguments of DragDropRegistry<...>, rewrites registry.scroll.pipe(...) and registry.scroll.subscribe(...) to the scrolled() method, and marks other uses of scroll, which relied on it being a Subject.
org.mod run .Install it once, then run it on every repository under the current directory. New to the Moderne CLI? Set it up.