feat(python): batch Ollama embed calls (#2453)

Other embedding integrations such as Cohere and OpenAI already send
requests in batches. We should do that for Ollama too to improve
throughput.

The Ollama [`.embed`
API](https://github.com/ollama/ollama-python/blob/63ca74762284100b2f0ad207bc00fa3d32720fbd/ollama/_client.py#L359-L378)
was added in version 0.3.0 (almost a year ago) so I updated the version
requirement in pyproject.

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **Bug Fixes**
- Improved compatibility with newer versions of the "ollama" package by
requiring version 0.3.0 or higher.
- Enhanced embedding generation to process batches of texts more
efficiently and reliably.
- **Refactor**
	- Improved type consistency and clarity for embedding-related methods.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

python/pyproject.toml

@@ -85,7 +85,7 @@ embeddings = [
     "boto3>=1.28.57",
     "awscli>=1.29.57",
     "botocore>=1.31.57",
-    "ollama",
+    "ollama>=0.3.0",
     "ibm-watsonx-ai>=1.1.2",
 ]
 azure = ["adlfs>=2024.2.0"]