perf(ext/event): always set timeStamp to 0 (#20191)

```js
Deno.bench(function eventNew() {
  new Event("foo");
});
```

<b>main</b>
```
./target/release/deno bench event_bench.js
cpu: Apple M1 Max
runtime: deno 1.36.1 (aarch64-apple-darwin)

file:///Users/ib/dev/deno/event_bench.js
benchmark      time (avg)        iter/s             (min … max)       p75       p99      p995
--------------------------------------------------------------- -----------------------------
eventNew       36.43 ns/iter  27,451,874.9   (35.15 ns … 46.98 ns)  37.68 ns   40.7 ns  41.69 ns

```

<b>this PR</b>
```
./target/release/deno bench event_bench.js
cpu: Apple M1 Max
runtime: deno 1.36.1 (aarch64-apple-darwin)

file:///Users/ib/dev/deno/event_bench.js
benchmark      time (avg)        iter/s             (min … max)       p75       p99      p995
--------------------------------------------------------------- -----------------------------
eventNew       13.71 ns/iter  72,958,970.0   (12.85 ns … 31.79 ns)  15.11 ns  16.49 ns   17.5 ns

```

Towards #20167

ext/web/02_event.js

@@ -21,7 +21,6 @@ const {
   ArrayPrototypeSplice,
   ArrayPrototypeUnshift,
   Boolean,
-  DateNow,
   Error,
   FunctionPrototypeCall,
   MapPrototypeGet,
@@ -123,8 +122,6 @@ const _inPassiveListener = Symbol("[[inPassiveListener]]");
 const _dispatched = Symbol("[[dispatched]]");
 const _isTrusted = Symbol("[[isTrusted]]");
 const _path = Symbol("[[path]]");
-// internal.
-const _skipInternalInit = Symbol("[[skipSlowInit]]");
 
 class Event {
   constructor(type, eventInitDict = {}) {
@@ -138,21 +135,6 @@ class Event {
     this[_isTrusted] = false;
     this[_path] = [];
 
-    if (eventInitDict?.[_skipInternalInit]) {
-      this[_attributes] = {
-        type,
-        data: eventInitDict.data ?? null,
-        bubbles: eventInitDict.bubbles ?? false,
-        cancelable: eventInitDict.cancelable ?? false,
-        composed: eventInitDict.composed ?? false,
-        currentTarget: null,
-        eventPhase: Event.NONE,
-        target: null,
-        timeStamp: 0,
-      };
-      return;
-    }
-
     webidl.requiredArguments(
       arguments.length,
       1,
@@ -172,7 +154,7 @@ class Event {
       currentTarget: null,
       eventPhase: Event.NONE,
       target: null,
-      timeStamp: DateNow(),
+      timeStamp: 0,
     };
   }
 
@@ -1205,7 +1187,6 @@ class MessageEvent extends Event {
       bubbles: eventInitDict?.bubbles ?? false,
       cancelable: eventInitDict?.cancelable ?? false,
       composed: eventInitDict?.composed ?? false,
-      [_skipInternalInit]: eventInitDict?.[_skipInternalInit],
     });
 
     this.data = eventInitDict?.data ?? null;
@@ -1494,7 +1475,6 @@ function reportError(error) {
 }
 
 export {
-  _skipInternalInit,
   CloseEvent,
   CustomEvent,
   defineEventHandler,

ext/websocket/01_websocket.js

@@ -9,7 +9,6 @@ import * as webidl from "ext:deno_webidl/00_webidl.js";
 import { HTTP_TOKEN_CODE_POINT_RE } from "ext:deno_web/00_infra.js";
 import DOMException from "ext:deno_web/01_dom_exception.js";
 import {
-  _skipInternalInit,
   CloseEvent,
   defineEventHandler,
   dispatch,
@@ -450,7 +449,6 @@ class WebSocket extends EventTarget {
           const event = new MessageEvent("message", {
             data,
             origin: this[_url],
-            [_skipInternalInit]: true,
           });
           setIsTrusted(event, true);
           dispatch(this, event);