events: remove eventtarget custom inspect branding

PR-URL: https://github.com/nodejs/node/pull/61128
Reviewed-By: Aviv Keller <me@aviv.sh>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

lib/internal/event_target.js

@@ -867,8 +867,6 @@ class EventTarget {
     return new CustomEvent(type, { detail: nodeValue });
   }
   [customInspectSymbol](depth, options) {
-    if (!isEventTarget(this))
-      throw new ERR_INVALID_THIS('EventTarget');
     const name = this.constructor.name;
     if (depth < 0)
       return name;

test/parallel/test-eventtarget-custom-inspect-does-not-throw.js

@@ -0,0 +1,19 @@
+'use strict';
+
+require('../common');
+const assert = require('assert');
+const util = require('util');
+
+const symbol = util.inspect.custom;
+
+const eventTargetInspect = EventTarget.prototype[symbol];
+
+const fakeEventTarget = {
+  [symbol]: eventTargetInspect,
+  someOtherField: 42
+};
+
+// Should not throw when calling the custom inspect method
+const output = util.inspect(fakeEventTarget);
+
+assert.strictEqual(typeof output, 'string');