Fix/bool checks (#1230)

### Description

Boolean checks were missing for a step's `is_create` and `is_root`
fields.

### Issue Link

Issue originated from Scroll's fork:
scroll-tech#325

### Type of change

- [x] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] This change requires a documentation update

zkevm-circuits/src/evm_circuit/execution.rs

@@ -399,6 +399,14 @@ impl<F: Field> ExecutionConfig<F> {
                     1.expr(),
                 )
             });
+            // For every step, is_create and is_root are boolean.
+            cb.condition(q_step.clone(), |cb| {
+                cb.require_boolean(
+                    "step.is_create is boolean",
+                    step_curr.state.is_create.expr(),
+                );
+                cb.require_boolean("step.is_root is boolean", step_curr.state.is_root.expr());
+            });
             // q_step needs to be enabled on the last row
             cb.condition(q_step_last, |cb| {
                 cb.require_equal("q_step == 1", q_step.clone(), 1.expr());