test(bedrock): move retrieve_batch dispatch test to tests/test_litellm/

The dispatch test landed under `tests/test_litellm/batches/`, a new
directory that no upstream `test-unit-*.yml` workflow's `test-path`
allow-list includes. As a result, the test was never executed in CI
and codecov reported `litellm/batches/main.py` patch coverage at
11.11% (8 lines uncovered) — the lines belonging to this PR's
dispatch refactor itself.

Move the file up one level so it matches the
`tests/test_litellm/test_*.py` glob that `test-unit-misc.yml`
already runs, and adjust `sys.path.insert` for the new depth.

The companion handler tests under
`tests/test_litellm/llms/bedrock/batches/test_handler.py` are
unaffected — they're picked up by the `llms` directory in
`test-unit-llm-providers.yml`.

Made-with: Cursor

tests/test_litellm/test_retrieve_batch_bedrock_dispatch.py

@@ -20,7 +20,7 @@ from unittest.mock import MagicMock, patch
 
 import pytest
 
-sys.path.insert(0, os.path.abspath("../../.."))
+sys.path.insert(0, os.path.abspath("../.."))
 
 import litellm  # noqa: E402