feat(AutoModeration): v13 support customMessage

#9173 djs

src/structures/AutoModerationRule.js

@@ -103,6 +103,7 @@ class AutoModerationRule extends Base {
        * @typedef {Object} AutoModerationActionMetadata
        * @property {?Snowflake} channelId The id of the channel to which content will be logged
        * @property {?number} durationSeconds The timeout duration in seconds
+       * @property {?string} customMessage The custom message that is shown whenever a message is blocked
        */
 
       /**
@@ -114,6 +115,7 @@ class AutoModerationRule extends Base {
         metadata: {
           durationSeconds: action.metadata.duration_seconds ?? null,
           channelId: action.metadata.channel_id ?? null,
+          customMessage: action.metadata.custom_message ?? null,
         },
       }));
     }