fix(deps): update dependency google-gax to v4.3.9 (#2094)

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This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| [google-gax](https://togithub.com/googleapis/gax-nodejs) ([source](https://togithub.com/googleapis/gax-nodejs/tree/HEAD/gax)) | [`4.3.8` -> `4.3.9`](https://renovatebot.com/diffs/npm/google-gax/4.3.8/4.3.9) | [![age](https://developer.mend.io/api/mc/badges/age/npm/google-gax/4.3.9?slim=true)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://developer.mend.io/api/mc/badges/adoption/npm/google-gax/4.3.9?slim=true)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://developer.mend.io/api/mc/badges/compatibility/npm/google-gax/4.3.8/4.3.9?slim=true)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://developer.mend.io/api/mc/badges/confidence/npm/google-gax/4.3.8/4.3.9?slim=true)](https://docs.renovatebot.com/merge-confidence/) |

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### Release Notes

<details>
<summary>googleapis/gax-nodejs (google-gax)</summary>

### [`v4.3.9`](https://togithub.com/googleapis/gax-nodejs/blob/HEAD/gax/CHANGELOG.md#439-2024-08-06)

[Compare Source](https://togithub.com/googleapis/gax-nodejs/compare/google-gax-v4.3.8...google-gax-v4.3.9)

##### Bug Fixes

-   reduce duplicate code in streaming retries and add a test ([#&#8203;1636](https://togithub.com/googleapis/gax-nodejs/issues/1636)) ([83b52e1](https://togithub.com/googleapis/gax-nodejs/commit/83b52e14ba3bb1e9f0e079ea53e47ec32b4cfd45))
-   test application cleanup ([#&#8203;1639](https://togithub.com/googleapis/gax-nodejs/issues/1639)) ([76ac496](https://togithub.com/googleapis/gax-nodejs/commit/76ac496fe42f1176df733d0adcc755bd4e773b10))

</details>

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package.json

@@ -66,7 +66,7 @@
     "events-intercept": "^2.0.0",
     "extend": "^3.0.2",
     "google-auth-library": "^9.0.0",
-    "google-gax": "4.3.8",
+    "google-gax": "4.3.9",
     "grpc-gcp": "^1.0.0",
     "is": "^3.2.1",
     "lodash.snakecase": "^4.1.1",