Remove unused code

packages/next/build/webpack-config.ts

@@ -19,7 +19,6 @@ import {
 import { fileExists } from '../lib/file-exists'
 import { getPackageVersion } from '../lib/get-package-version'
 import { CustomRoutes } from '../lib/load-custom-routes.js'
-import { getTypeScriptConfiguration } from '../lib/typescript/getTypeScriptConfiguration'
 import {
   CLIENT_STATIC_FILES_RUNTIME_AMP,
   CLIENT_STATIC_FILES_RUNTIME_MAIN,
@@ -87,33 +86,6 @@ const devtoolRevertWarning = execOnce(
 
 let loggedSwcDisabled = false
 
-function parseJsonFile(filePath: string) {
-  const JSON5 = require('next/dist/compiled/json5')
-  const contents = readFileSync(filePath, 'utf8')
-
-  // Special case an empty file
-  if (contents.trim() === '') {
-    return {}
-  }
-
-  try {
-    return JSON5.parse(contents)
-  } catch (err) {
-    if (!isError(err)) throw err
-    const codeFrame = codeFrameColumns(
-      String(contents),
-      {
-        start: {
-          line: (err as Error & { lineNumber?: number }).lineNumber || 0,
-          column: (err as Error & { columnNumber?: number }).columnNumber || 0,
-        },
-      },
-      { message: err.message, highlightCode: true }
-    )
-    throw new Error(`Failed to parse "${filePath}":\n${codeFrame}`)
-  }
-}
-
 function getOptimizedAliases(): { [pkg: string]: string } {
   const stubWindowFetch = path.join(__dirname, 'polyfills', 'fetch', 'index.js')
   const stubObjectAssign = path.join(__dirname, 'polyfills', 'object-assign.js')
@@ -232,8 +204,6 @@ export const NODE_BASE_ESM_RESOLVE_OPTIONS = {
   alias: false,
 }
 
-let TSCONFIG_WARNED = false
-
 export const nextImageLoaderRegex =
   /\.(png|jpg|jpeg|gif|webp|avif|ico|bmp|svg)$/i