community: add OCI Endpoint (#14250)
- **Description:**
- [OCI Data
Science](https://docs.oracle.com/en-us/iaas/data-science/using/home.htm)
is a fully managed and serverless platform for data science teams to
build, train, and manage machine learning models in the Oracle Cloud
Infrastructure. This PR add integration for using LangChain with an LLM
hosted on a [OCI Data Science Model
Deployment](https://docs.oracle.com/en-us/iaas/data-science/using/model-dep-about.htm).
To authenticate,
[oracle-ads](https://accelerated-data-science.readthedocs.io/en/latest/user_guide/cli/authentication.html)
has been used to automatically load credentials for invoking endpoint.
- **Issue:** None
- **Dependencies:** `oracle-ads`
- **Tag maintainer:** @baskaryan
- **Twitter handle:** None
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Co-authored-by: Erick Friis <erick@langchain.dev>
