This just makes an additional simplification after [[https://github.com/bitcoin/bitcoin/pull/21366 | core#21366]] replaced `util::Ref` with `std::any`.
Note that we sometimes wrap the context in a `HTTPRPCRequestProcessor`instance, so some changes don't apply in bitcoind.cpp and init.cpp.
This is a backport of [[https://github.com/bitcoin/bitcoin/pull/21574 | core#21574]]
Depends on D11552