chore: Remove outdated comment (#1306)

remove outdated comment

crates/noirc_evaluator/src/lib.rs

@@ -313,10 +313,6 @@ impl Evaluator {
     /// However, this intermediate representation is useful as it allows us to have
     /// intermediate Types which the core type system does not know about like Strings.
     fn parse_abi_alt(&mut self, ir_gen: &mut IrGenerator) {
-        // XXX: Currently, the syntax only supports public witnesses
-        // u8 and arrays are assumed to be private
-        // This is not a short-coming of the ABI, but of the grammar
-        // The new grammar has been conceived, and will be implemented.
         let main = ir_gen.program.main_mut();
         let main_params = std::mem::take(&mut main.parameters);
         let abi_params = std::mem::take(&mut ir_gen.program.main_function_signature.0);