[BUG] Error page is learned when the site accessed by playwright is not HTTP Status 200

## Describe the bug

https://github.com/aws-samples/bedrock-claude-chat/blob/02473ad46fc6fc0804d72dc44e75cc0a21cbb39c/backend/embedding/loaders/playwright.py#L156

```python
if response.status != 200:
raise ValueError(f"page.goto() returned Not HTTP Status 200 for url {url}")
```
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A clear and concise description of what the bug is.

## To Reproduce

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Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

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## Additional context

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