refactor(azure.py): replaces the custom transport logic for just using our httpx client

Done to fix all the http/https proxy issues people are facing with proxy.

litellm/tests/test_image_generation.py

@@ -1,20 +1,23 @@
 # What this tests?
 ## This tests the litellm support for the openai /generations endpoint
 
-import sys, os
-import traceback
-from dotenv import load_dotenv
 import logging
+import os
+import sys
+import traceback
+
+from dotenv import load_dotenv
 
 logging.basicConfig(level=logging.DEBUG)
 load_dotenv()
-import os
 import asyncio
+import os
 
 sys.path.insert(
     0, os.path.abspath("../..")
 )  # Adds the parent directory to the system path
 import pytest
+
 import litellm
 
 
@@ -39,9 +42,10 @@ def test_image_generation_openai():
 # test_image_generation_openai()
 
 
-def test_image_generation_azure():
+@pytest.mark.asyncio
+async def test_image_generation_azure():
     try:
-        response = litellm.image_generation(
+        response = await litellm.aimage_generation(
             prompt="A cute baby sea otter",
             model="azure/",
             api_version="2023-06-01-preview",