docs: fix "to to" duplicate-word typo in _api_client docstrings

[devteamaegis]

Summary

Three identical `Args:` docstrings in `google/genai/_api_client.py` (lines 1010, 1062, 1120) contain a duplicated `to`:

```diff

•    args: The client args to to check for SSL context.
  

•    args: The client args to check for SSL context.
  

```

Each instance is the docstring for a nested `_maybe_set` helper inside the three `ensure*_ssl_ctx` static methods on `BaseApiClient`. The three sibling `options.async_client_args` docstrings (lines 1038, etc.) already use the correct "to check", so this PR brings the nested ones into line.

Diff is exactly 3 lines, docstring-only — no runtime behaviour changes.

Novelty check

`gh search prs --repo googleapis/python-genai "to to check"` returned no matches. No open PR touches these lines.

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