Remove ListStream type (#14425)

# Description
List values and list streams have the same type (`list<>`). Rather,
streaming is a separate property of the pipeline/command output. This PR
removes the unnecessary `ListStream` type.

# User-Facing Changes
Should be none, except `random dice` now has a more specific output
type.

crates/nu-parser/src/type_check.rs

@@ -29,8 +29,6 @@ pub fn type_compatible(lhs: &Type, rhs: &Type) -> bool {
 
     match (lhs, rhs) {
         (Type::List(c), Type::List(d)) => type_compatible(c, d),
-        (Type::ListStream, Type::List(_)) => true,
-        (Type::List(_), Type::ListStream) => true,
         (Type::List(c), Type::Table(table_fields)) => {
             if matches!(**c, Type::Any) {
                 return true;