Remove use of deprecated getChildNodesByType method

deob-ast/src/main/java/dev/openrs2/deob/ast/util/ExprUtils.java

@@ -80,9 +80,11 @@ public final class ExprUtils {
 			count++;
 		}
 
-		for (Expression child : expr.getChildNodesByType(Expression.class)) {
+		for (Expression child : expr.findAll(Expression.class)) {
+			if (child != expr) {
 				count += countNots(child);
 			}
+		}
 
 		return count;
 	}