Optimize Edge SSR bundle size (#38570)

Both `Buffer` and `node-html-parser` are not necessary to be introduced to the Edge SSR bundle. This makes the bundle size 25% smaller.

## Bug

- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`

## Feature

- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have helpful link attached, see `contributing.md`

## Documentation / Examples

- [ ] Make sure the linting passes by running `pnpm lint`
- [ ] The examples guidelines are followed from [our contributing doc](https://github.com/vercel/next.js/blob/canary/contributing.md#adding-examples)

packages/next/pages/_document.tsx

@@ -970,7 +970,10 @@ export class NextScript extends Component<OriginProps> {
     const { __NEXT_DATA__, largePageDataBytes } = context
     try {
       const data = JSON.stringify(__NEXT_DATA__)
-      const bytes = Buffer.from(data).byteLength
+      const bytes =
+        process.env.NEXT_RUNTIME === 'edge'
+          ? new TextEncoder().encode(data).buffer.byteLength
+          : Buffer.from(data).byteLength
       const prettyBytes = require('../lib/pretty-bytes').default
 
       if (largePageDataBytes && bytes > largePageDataBytes) {

packages/next/server/post-process.ts

@@ -1,17 +1,22 @@
 import type { RenderOpts } from './render'
-import { parse, HTMLElement } from 'next/dist/compiled/node-html-parser'
+import type { HTMLElement } from 'next/dist/compiled/node-html-parser'
+
 import { OPTIMIZED_FONT_PROVIDERS } from '../shared/lib/constants'
 import { nonNullable } from '../lib/non-nullable'
 
 let optimizeAmp: typeof import('./optimize-amp').default | undefined
 let getFontDefinitionFromManifest:
   | typeof import('./font-utils').getFontDefinitionFromManifest
   | undefined
+let parse: typeof import('next/dist/compiled/node-html-parser').parse
 
 if (process.env.NEXT_RUNTIME !== 'edge') {
   optimizeAmp = require('./optimize-amp').default
   getFontDefinitionFromManifest =
     require('./font-utils').getFontDefinitionFromManifest
+  parse = (
+    require('next/dist/compiled/node-html-parser') as typeof import('next/dist/compiled/node-html-parser')
+  ).parse
 }
 
 type postProcessOptions = {