Capture exceptions in LangGraph integration

[antonpirker]

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

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

[linear[bot]]

PY-1850 Capture exceptions in LangGraph integration