Remove deprecated syntax (#6561)

* Remove deprecated syntax

Signed-off-by: Nick Cameron <nrc@ncameron.org>

* fix one test

* fix sketch on revolved face test

* fix test: empty-scene default-planes act as expected

* fix up more tests

* another fix

* remove another const

---------

Signed-off-by: Nick Cameron <nrc@ncameron.org>
Co-authored-by: Kurt Hutten Irev-Dev <k.hutten@protonmail.ch>

rust/kcl-lib/src/walk/ast_node.rs

@@ -313,11 +313,11 @@ mod tests {
     fn check_ptr_eq() {
         let program = kcl!(
             "
-const foo = 1
-const bar = foo + 1
+foo = 1
+bar = foo + 1
 
-fn myfn = () => {
-    const foo = 2
+fn myfn() {
+    foo = 2
     sin(foo)
 }
 "