fix(test): replace flaky test_vertex_ai_gemini_audio_ogg with mocked version

Previously made a real Vertex AI call with a Wikimedia URL that intermittently
failed with URL_REJECTED-REJECTED_FC_TIMEOUT.

Now mocks HTTPHandler.post and VertexBase._ensure_access_token so the test
verifies the translation (OGG -> file_data with audio/ogg mime_type) without
any real network calls. Runs in ~0.36s instead of ~60s.

tests/local_testing/test_amazing_vertex_completion.py

@@ -3891,30 +3891,77 @@ def test_vertex_ai_gemini_2_5_pro_streaming():
 
 
 def test_vertex_ai_gemini_audio_ogg():
-    load_vertex_ai_credentials()
-    litellm._turn_on_debug()
-    response = completion(
-        model="vertex_ai/gemini-2.0-flash",
-        messages=[
+    """
+    Test that OGG audio files are correctly formatted as file_data with audio/ogg mime type
+    in the request sent to Vertex AI. Uses mocked HTTP and auth to avoid flaky external
+    URL fetches and credential requirements.
+    """
+    from litellm.llms.custom_httpx.http_handler import HTTPHandler
+    from litellm.llms.vertex_ai.vertex_llm_base import VertexBase
+
+    mock_response = MagicMock()
+    mock_response.status_code = 200
+    mock_response.headers = {"Content-Type": "application/json"}
+    mock_response.json.return_value = {
+        "candidates": [
             {
-                "content": [
-                    {"text": "generate a transcript of the speech.", "type": "text"}
-                ],
-                "role": "user",
-            },
-            {
-                "content": [
-                    {
-                        "file": {
-                            "file_id": "https://upload.wikimedia.org/wikipedia/commons/5/5f/En-us-public.ogg"
-                        },
-                        "type": "file",
-                    }
-                ],
-                "role": "user",
-            },
+                "content": {
+                    "parts": [{"text": "public domain audio file"}],
+                    "role": "model",
+                },
+                "finishReason": "STOP",
+            }
         ],
-    )
+        "usageMetadata": {
+            "promptTokenCount": 10,
+            "candidatesTokenCount": 5,
+            "totalTokenCount": 15,
+        },
+    }
+
+    client = HTTPHandler()
+    httpx_mock = MagicMock(return_value=mock_response)
+
+    with patch.object(client, "post", new=httpx_mock), patch.object(
+        VertexBase, "_ensure_access_token", return_value=("fake-token", "fake-project")
+    ):
+        response = completion(
+            model="vertex_ai/gemini-2.0-flash",
+            messages=[
+                {
+                    "content": [
+                        {"text": "generate a transcript of the speech.", "type": "text"}
+                    ],
+                    "role": "user",
+                },
+                {
+                    "content": [
+                        {
+                            "file": {
+                                "file_id": "https://upload.wikimedia.org/wikipedia/commons/5/5f/En-us-public.ogg"
+                            },
+                            "type": "file",
+                        }
+                    ],
+                    "role": "user",
+                },
+            ],
+            client=client,
+        )
+
+    httpx_mock.assert_called_once()
+    request_body = httpx_mock.call_args.kwargs["json"]
+    # Verify OGG file is sent as file_data with correct mime type
+    file_data_parts = [
+        part
+        for content in request_body["contents"]
+        for part in content["parts"]
+        if "file_data" in part
+    ]
+    assert len(file_data_parts) == 1, f"Expected 1 file_data part, got: {file_data_parts}"
+    file_data = file_data_parts[0]["file_data"]
+    assert file_data["mime_type"] == "audio/ogg", f"Expected audio/ogg, got: {file_data['mime_type']}"
+    assert "En-us-public.ogg" in file_data["file_uri"], f"Unexpected file_uri: {file_data['file_uri']}"
     print(response)