worker: throw InvalidStateError in postMessage after close

Align BroadcastChannel behavior with the spec by throwing an
InvalidStateError when postMessage is called after the channel is
closed. This ensures that BroadcastChannel properly handles closed
states and throws the correct error for postMessage attempts.

This update addresses expected failures for invalid postMessage after close in WPT.

Author: Nahee-Park

lib/internal/worker/io.js

@@ -402,7 +402,7 @@ class BroadcastChannel extends EventTarget {
     if (arguments.length === 0)
       throw new ERR_MISSING_ARGS('message');
     if (this[kHandle] === undefined)
-      throw new DOMException('BroadcastChannel is closed.');
+      throw new DOMException('BroadcastChannel is closed.', 'InvalidStateError');
     if (this[kHandle].postMessage(message) === undefined)
       throw new DOMException('Message could not be posted.');
   }

test/wpt/status/webmessaging/broadcastchannel.json

@@ -10,14 +10,6 @@
       ]
     }
   },
-  "interface.any.js": {
-    "fail": {
-      "expected": [
-        "postMessage after close should throw",
-        "postMessage should throw InvalidStateError after close, even with uncloneable data"
-      ]
-    }
-  },
   "origin.window.js": {
     "fail": {
       "expected": [