test: drop the streaming iterator enqueue test, now covered upstream

_handle_streaming_logging already enqueues the end-of-stream logging
coroutine on GLOBAL_LOGGING_WORKER on main, so the assertion no longer
belongs to this change. What remains here is the standard_logging_object
fallback in litellm_logging.py, which main still does not handle: the
build can return None (exceptions are swallowed inside
get_standard_logging_object_payload) and loggers gated on that key drop
the request while spend tracking still succeeds.

tests/unit/llms/anthropic/pass_through/messages/test_streaming_iterator_logging.py

@@ -1,37 +0,0 @@
-"""
-Regression test for https://github.com/BerriAI/litellm/issues/32019.
-
-End-of-stream logging for /v1/messages must be enqueued on the logging
-worker instead of a bare ``asyncio.create_task``: an unreferenced task can
-be garbage-collected before it runs, dropping the success log entirely
-(same class of bug fixed for pass-through routes in #31485).
-"""
-
-from unittest.mock import MagicMock
-
-import pytest
-
-from litellm.litellm_core_utils.logging_worker import GLOBAL_LOGGING_WORKER
-from litellm.llms.anthropic.experimental_pass_through.messages.streaming_iterator import (
-    BaseAnthropicMessagesStreamingIterator,
-)
-
-
-@pytest.mark.asyncio
-async def test_handle_streaming_logging_enqueues_on_logging_worker(monkeypatch):
-    enqueued = []
-
-    def fake_enqueue(async_coroutine):
-        enqueued.append(async_coroutine)
-        async_coroutine.close()
-
-    monkeypatch.setattr(GLOBAL_LOGGING_WORKER, "ensure_initialized_and_enqueue", fake_enqueue)
-
-    iterator = BaseAnthropicMessagesStreamingIterator(
-        litellm_logging_obj=MagicMock(),
-        request_body={"model": "claude-3-5-sonnet-20240620", "stream": True},
-    )
-
-    await iterator._handle_streaming_logging(collected_chunks=[b"data: {}\n\n"])
-
-    assert len(enqueued) == 1