feat: Adding OCI Embeddings (#4300)

# What does this PR do?
Enabling usage of OCI embedding models.

## Test Plan
Testing embedding model:
`OCI_COMPARTMENT_OCID="" OCI_REGION="us-chicago-1"
OCI_AUTH_TYPE=config_file pytest -sv
tests/integration/inference/test_openai_embeddings.py --stack-config oci
--embedding-model oci/openai.text-embedding-3-small --inference-mode
live`

Testing chat model:
`OCI_COMPARTMENT_OCID="" OCI_REGION="us-chicago-1"
OCI_AUTH_TYPE=config_file pytest -sv tests/integration/inference/
--stack-config oci --text-model oci/openai.gpt-4.1-nano-2025-04-14
--inference-mode live`

Testing curl for embeddings:
`curl -X POST http://localhost:8321/v1/embeddings -H "Content-Type:
application/json" -d '{
  "model": "oci/openai.text-embedding-3-small",
  "input": ["First text", "Second text"],
  "encoding_format": "float"
}'`

`{"object":"list","data":[{"object":"embedding","embedding":[-0.017190756...0.025272394],"index":1}],"model":"oci/openai.text-embedding-3-small","usage":{"prompt_tokens":4,"total_tokens":4}}`

---------

Co-authored-by: Omar Abdelwahab <omaryashraf10@gmail.com>

tests/integration/inference/test_openai_embeddings.py

@@ -138,7 +138,6 @@ def skip_if_model_doesnt_support_openai_embeddings(client, model_id):
         "remote::runpod",
         "remote::sambanova",
         "remote::tgi",
-        "remote::oci",
     ):
         pytest.skip(f"Model {model_id} hosted by {provider.provider_type} doesn't support OpenAI embeddings.")