lib: Event static properties non configurable and writable

The idl definition for Event makes the properties constants, this means
that they shouldn't be configurable. However, they were, and this commit
fixes that.

Fixes: nodejs#50417

lib/internal/event_target.js

@@ -354,6 +354,33 @@ ObjectDefineProperties(
     isTrusted: isTrustedDescriptor,
   });
 
+  Object.defineProperties(Event, {
+    NONE: {
+      writable: false,
+      configurable: false,
+      enumerable: true,
+      value: 0,
+    },
+    CAPTURING_PHASE: {
+      writable: false,
+      configurable: false,
+      enumerable: true,
+      value: 1,
+    },
+    AT_TARGET: {
+      writable: false,
+      configurable: false,
+      enumerable: true,
+      value: 2,
+    },
+    BUBBLING_PHASE: {
+      writable: false,
+      configurable: false,
+      enumerable: true,
+      value: 3,
+    }
+  });
+
 function isCustomEvent(value) {
   return isEvent(value) && (value?.[kDetail] !== undefined);
 }

test/parallel/test-event.js

@@ -0,0 +1,11 @@
+'use strict';
+const assert = require('assert');
+
+const props = ['NONE', 'CAPTURING_PHASE', 'AT_TARGET', 'BUBBLING_PHASE']
+
+for (const prop of props) {
+  const desc = Object.getOwnPropertyDescriptor(Event, prop)
+  assert.strictEqual(desc.writable, false)
+  assert.strictEqual(desc.configurable, false)
+  assert.strictEqual(desc.enumerable, true)
+}