Support gRPC interface of TEI

[mhillebrand]

The gRPC interface of HuggingFace's Text Embeddings Inference (TEI) library is much, much faster than its HTTP interface. It would be fantastic to see Haystack add support for it.

https://github.com/huggingface/text-embeddings-inference?tab=readme-ov-file#grpc

[anakin87]

Nice idea!

I had a look and seems non-trivial because we are currently using the huggingface_hub library to send requests to TEI and this library does not seem to support gRPC.

Let's see if they will introduce this feature...