I forgot about those lines too! I put in valves in the basement that allow me to drain the lines in the winter and not have water up into the bedroom closet. Since I haven't put in the W/D, I don't use the lines at all. The valves make winterizing much easier too.
These are similar to what I have...
https://www.lowes.com/pd/SharkBite-1...E&gclsrc=aw.ds