Fix saving issue on invalid conditional rule (#8091)

Fixes #8083

app/src/composables/use-item/use-item.ts

@@ -322,6 +322,7 @@ export function useItem(collection: Ref<string>, primaryKey: Ref<string | number
 				const conditions = [...field.meta.conditions].reverse();
 
 				const matchingCondition = conditions.find((condition) => {
+					if (!condition.rule || Object.keys(condition.rule).length !== 1) return;
 					const errors = validatePayload(condition.rule, item, { requireAll: true });
 					return errors.length === 0;
 				});