fix: proper check for plugin in tsconfig (#45831)

`plugin` is a key of `tsconfig.compilerOptions`

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## Bug

- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have a helpful link attached, see
[`contributing.md`](https://github.com/vercel/next.js/blob/canary/contributing.md)

## Feature

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PR.
- [ ] Related issues linked using `fixes #number`
- [ ]
[e2e](https://github.com/vercel/next.js/blob/canary/contributing/core/testing.md#writing-tests-for-nextjs)
tests added
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- [ ] Errors have a helpful link attached, see
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## Documentation / Examples

- [ ] Make sure the linting passes by running `pnpm build && pnpm lint`
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---------

packages/next/src/lib/typescript/writeConfigurationDefaults.ts

@@ -198,7 +198,10 @@ export async function writeConfigurationDefaults(
       // If the TS config extends on another config, we can't add the `plugin` field
       // because that will override the parent config's plugins.
       // Instead we have to show a message to the user to add the plugin manually.
-      if ('extends' in userTsConfig && !('plugins' in userTsConfig)) {
+      if (
+        'extends' in userTsConfig &&
+        !('plugins' in userTsConfig.compilerOptions)
+      ) {
         console.log(
           `\nYour ${chalk.cyan(
             'tsconfig.json'