test(api): move vector-store signature tests out of generated code (#3707)

- [x] I understand that this repository is auto-generated and my pull
request may not be merged

## Changes being requested

Move the three handwritten vector-store helper-signature tests into
handwritten
test modules, then restore the two API-resource test files to the
recorded
public generated snapshot. Keep each original function, decorator,
comparison,
and excluded-parameter set unchanged.

Only four test files change. No polling, upload, runtime, dependency,
API
reference, compiler, or generation-metadata changes.

## Additional context & links

The exact retained coverage is:

-
[`tests/lib/test_vector_store_file_batches.py::test_create_and_poll_method_in_sync`](https://github.com/openai/openai-python/blob/8eaeaad036a156bbd4155c6a426acffa06d13cfd/tests/lib/test_vector_store_file_batches.py#L10)
  keeps batch `create_and_poll` aligned with `create`.
-
[`tests/lib/test_vector_store_files.py::test_create_and_poll_method_in_sync`](https://github.com/openai/openai-python/blob/8eaeaad036a156bbd4155c6a426acffa06d13cfd/tests/lib/test_vector_store_files.py#L10)
  keeps file `create_and_poll` aligned with `create`.
-
[`tests/lib/test_vector_store_files.py::test_upload_and_poll_method_in_sync`](https://github.com/openai/openai-python/blob/8eaeaad036a156bbd4155c6a426acffa06d13cfd/tests/lib/test_vector_store_files.py#L20)
keeps `upload_and_poll` aligned with `create`, retaining exactly the
existing
exclusions: `file_id`, `extra_headers`, `extra_query`, `extra_body`, and
  `timeout`.

Each still runs for both sync and async clients: all **six original
cases** are
preserved. The generated API tests remain intact.

Validation:

- Exact-source/AST proof, including decorators and exclusions; both
generated
  files match the public snapshot byte-for-byte.
- Both Pydantic collection checks preserve all six original test IDs
after
  mapping only the file paths.
- The two handwritten modules plus both affected API-resource suites
pass
**226 tests under Pydantic v2 and 226 under v1**, against the checked-in
API
  mock.
- `./scripts/format` and `./scripts/lint` pass, including Ruff, Pyright,
mypy,
and import checks. Unrelated reporter-only formatting changes are
excluded.
- Verified public custom-code report: **40 → 38 mixed files**, exactly
these
  two customizations removed and every other customization unchanged.