Revert "Update Groovy 4 release notes (show JEP 406 support)"

This reverts commit 7a136cab
diff --git a/site/src/site/releasenotes/groovy-4.0.adoc b/site/src/site/releasenotes/groovy-4.0.adoc
index 01ba2d7..685b489 100644
--- a/site/src/site/releasenotes/groovy-4.0.adoc
+++ b/site/src/site/releasenotes/groovy-4.0.adoc
@@ -220,12 +220,14 @@
 @Immutable class MulExpr implements Expr { Expr left, right }
 
 int eval(Expr e) {
-    switch(e) {
-        case IntExpr(i) -> i
-        case NegExpr(n) -> -eval(n)
-        case AddExpr(left, right) -> eval(left) + eval(right)
-        case MulExpr(left, right) -> eval(left) * eval(right)
-        default -> throw new IllegalStateException()
+    e.with {
+        switch(it) {
+            case IntExpr -> i
+            case NegExpr -> -eval(n)
+            case AddExpr -> eval(left) + eval(right)
+            case MulExpr -> eval(left) * eval(right)
+            default -> throw new IllegalStateException()
+        }
     }
 }