[Fix] Batches Tests: Remove VCR Auto-Marker

Strip VCR wiring from the batches test conftest. Drops:

- import of `_vcr_conftest_common` helpers
- the `vcr_config` fixture, `pytest_recording_configure`,
  `_vcr_outcome_gate`, `pytest_runtest_makereport`
- the `apply_vcr_auto_marker_to_items` call in
  `pytest_collection_modifyitems`
- `VerboseReporterState` / its `pytest_configure` /
  `pytest_runtest_logreport` hooks (purely VCR-verdict plumbing)

Why: every test in this directory creates ephemeral OpenAI / Bedrock /
vLLM resources whose IDs change per run (file-XXX, batch-XXX,
ft-XXX, ...). VCR's path/query/body matchers don't match across runs,
so `record_mode="new_episodes"` was silently passing through to the
live API and recording many new cassette entries every run. Cassette
bloat without replay benefit.

Behaviour after this change is identical to running the directory
without `CASSETTE_REDIS_URL` set: tests that have keys hit live APIs,
tests that don't continue to skip via their existing skipif markers.

Conftest now keeps only path setup and the session-scoped `event_loop`
fixture.

tests/batches_tests/conftest.py

@@ -1,7 +1,6 @@
 # conftest.py
 
 import asyncio
-import importlib
 import os
 import sys
 
@@ -12,16 +11,6 @@ sys.path.insert(
 )  # Adds the parent directory to the system path
 import litellm  # noqa: E402,F401
 
-from tests._vcr_conftest_common import (  # noqa: E402
-    VerboseReporterState,
-    apply_vcr_auto_marker_to_items,
-    record_vcr_outcome,
-    register_persister_if_enabled,
-    vcr_config_dict,
-)
-
-_verbose_state = VerboseReporterState()
-
 
 @pytest.fixture(scope="session")
 def event_loop():
@@ -31,37 +20,3 @@ def event_loop():
         loop = asyncio.new_event_loop()
     yield loop
     loop.close()
-
-
-@pytest.fixture(scope="module")
-def vcr_config():
-    return vcr_config_dict()
-
-
-def pytest_recording_configure(config, vcr):
-    register_persister_if_enabled(vcr)
-
-
-@pytest.hookimpl(hookwrapper=True)
-def pytest_runtest_makereport(item, call):
-    outcome = yield
-    rep = outcome.get_result()
-    setattr(item, f"rep_{rep.when}", rep)
-
-
-@pytest.fixture(autouse=True)
-def _vcr_outcome_gate(request, vcr):
-    yield
-    record_vcr_outcome(request, vcr)
-
-
-def pytest_configure(config):
-    _verbose_state.remember_pluginmanager(config)
-
-
-def pytest_runtest_logreport(report):
-    _verbose_state.maybe_emit_verdict(report)
-
-
-def pytest_collection_modifyitems(config, items):
-    apply_vcr_auto_marker_to_items(items)