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