Capture exceptions in LangGraph integration

The current LangGraph integration does not capture errors right now. If we are hooked into a function that can raise unhandled exceptions we should capture them.

Similar to here:

[https://github.com/getsentry/sentry-python/blob/master/sentry_sdk/integrations/anthropic.py#L344-L348](https://github.com/getsentry/sentry-python/blob/master/sentry_sdk/integrations/anthropic.py#L344-L348)

Also make sure that the `span.status` in that case is set to `"error"` like it done for the other AI integrations in this PR:
getsentry/sentry-python#4820

首先定位 LangGraph 整合，並將其例外處理與 sentry_sdk/integrations/anthropic.py 第 344-348 行附近的實作進行比較。查看 getsentry/sentry-python#4820，了解相應的 AI 整合行為。當未處理的例外被捕獲且 span.status 被設定為 "error" 時，即表示完成。

由索引模型根據 Issue 內容生成。