LocalAI embedding models.
Since LocalAI and OpenAI have 1:1 compatibility between APIs, this class
uses the openai Python package's openai.Embedding as its client.
Thus, you should have the openai python package installed, and defeat
the environment variable OPENAI_API_KEY by setting to a random string.
You also need to specify OPENAI_API_BASE to point to your LocalAI
service endpoint.