Remove it expansion (#2701)

* Remove it-expansion, take 2

* Cleanup

* silly update to test CI

crates/nu-cli/tests/commands/keep/rows.rs

@@ -23,7 +23,6 @@ fn rows() {
                 | keep 3
                 | get lucky_code
                 | math sum
-                | echo $it
                 "#
         ));