[Bug]: Unable to deploy Next.js following official guide

### Problem description

Unable to deploy next.js apps on deno deploy through the cli or github actions.

I've tried following [this guide](https://deno.com/blog/nextjs-on-deno-deploy) and several other methods but always get the same type of parsing error:

```
Uploading 58 asset(s) (80.1%)
Uploading 58 asset(s) (80.1%)
Uploading 58 asset(s) (100.0%)
Uploading 58 asset(s) (100.0%)
Deploying... (100.0%)
Error: The deployment failed: Error parsing 'file:///src/.next/server/pages/404.html': Expected ';', '}' or at file:///src/.next/server/pages/404.html:1:11

5. Observe error in [deploy action](https://github.com/alexbatis/deploy-deno/actions/runs/13795519113/job/38586093664)
```
Uploading 58 asset(s) (80.1%)
Uploading 58 asset(s) (80.1%)
Uploading 58 asset(s) (100.0%)
Uploading 58 asset(s) (100.0%)
Deploying... (100.0%)
Error: The deployment failed: Error parsing 'file:///src/.next/server/pages/404.html': Expected ';', '}' or at file:///src/.next/server/pages/404.html:1:11

### Additional context

it seems like others are encountering this as well

- @kamekyame - [posts](https://zenn.dev/suzutomo/scraps/854aa03d801b87), [failed deploy github action](https://github.com/kamekyame/deploy-deno-test/commit/393f06b7ba382bb5a22d962d4dcc3758be4e7522#commitcomment-152957942)

- https://questions.deno.com/m/1346803822302990336