Given that it is a conffile, you can remove the one you do not need.
Why do you want to use resolvconf, instead of resolved? I was expecting for people to have /etc/resolv.conf to point at either /run/systemd/resolve/stub-resolv.conf or /run/systemd/resolve/resolv.conf (as needed) and have nameservers updated via that.
Given that it is a conffile, you can remove the one you do not need.
Why do you want to use resolvconf, instead of resolved? I was expecting for people to have /etc/resolv.conf to point at either /run/systemd/ resolve/ stub-resolv. conf or /run/systemd/ resolve/ resolv. conf (as needed) and have nameservers updated via that.