Supporting Langchain Langgraph 1.0

Thanks for stopping by to let us know something could be better! **PLEASE READ**: If you have a support contract with Google, please create an issue in the [support console](https://cloud.google.com/support/) instead of filing on GitHub. This will ensure a timely response. **Is your feature request related to a problem? Please describe.** Trying to use Google Cloud SQL for PostgresSQL together with Langchain & Langgraph 1.0, and now this package doesn't support 1.0. **Describe the solution you'd like** Have the package updated to support Langchain & Langgraph 1.0 **Describe alternatives you've considered** Continue using Langchain's Postgres packages for checkpointers and stores to connect Cloud SQL. If find it too hard to use, considering switching to other platforms that has better support of Langchain & Langgraph 1.0 **Additional context** Leaving this blank for now.