chore: use rw.WriteHeader to write responses without bodies (#13870)

coderd/workspaces.go

@@ -927,9 +927,7 @@ func (api *API) putWorkspaceDormant(rw http.ResponseWriter, r *http.Request) {
 
 	// If the workspace is already in the desired state do nothing!
 	if workspace.DormantAt.Valid == req.Dormant {
-		httpapi.Write(ctx, rw, http.StatusNotModified, codersdk.Response{
-			Message: "Nothing to do!",
-		})
+		rw.WriteHeader(http.StatusNotModified)
 		return
 	}