deps: update google.core.version to v2.8.4 (#762)

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This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| [com.google.cloud:google-cloud-core](https://togithub.com/googleapis/java-core) | `2.8.3` -> `2.8.4` | [![age](https://badges.renovateapi.com/packages/maven/com.google.cloud:google-cloud-core/2.8.4/age-slim)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://badges.renovateapi.com/packages/maven/com.google.cloud:google-cloud-core/2.8.4/adoption-slim)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://badges.renovateapi.com/packages/maven/com.google.cloud:google-cloud-core/2.8.4/compatibility-slim/2.8.3)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://badges.renovateapi.com/packages/maven/com.google.cloud:google-cloud-core/2.8.4/confidence-slim/2.8.3)](https://docs.renovatebot.com/merge-confidence/) |
| [com.google.cloud:google-cloud-core-bom](https://togithub.com/googleapis/java-core) | `2.8.3` -> `2.8.4` | [![age](https://badges.renovateapi.com/packages/maven/com.google.cloud:google-cloud-core-bom/2.8.4/age-slim)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://badges.renovateapi.com/packages/maven/com.google.cloud:google-cloud-core-bom/2.8.4/adoption-slim)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://badges.renovateapi.com/packages/maven/com.google.cloud:google-cloud-core-bom/2.8.4/compatibility-slim/2.8.3)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://badges.renovateapi.com/packages/maven/com.google.cloud:google-cloud-core-bom/2.8.4/confidence-slim/2.8.3)](https://docs.renovatebot.com/merge-confidence/) |

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### Release Notes

<details>
<summary>googleapis/java-core</summary>

### [`v2.8.4`](https://togithub.com/googleapis/java-core/blob/HEAD/CHANGELOG.md#&#8203;284-httpsgithubcomgoogleapisjava-corecomparev283v284-2022-07-27)

[Compare Source](https://togithub.com/googleapis/java-core/compare/v2.8.3...v2.8.4)

##### Documentation

-   update javadocs for ReadChannel#limit to be more clear ([#&#8203;880](https://togithub.com/googleapis/java-core/issues/880)) ([c7de4e2](https://togithub.com/googleapis/java-core/commit/c7de4e2871d6a32cacc7aab69d826f3afd6301ef))

##### Dependencies

-   Update google-cloud-shared-config to v1.5.3 ([#&#8203;882](https://togithub.com/googleapis/java-core/issues/882)) ([aabb0b4](https://togithub.com/googleapis/java-core/commit/aabb0b42076f8a02e7b31d604add567fa909df6c))

</details>

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first-party-dependencies/pom.xml

@@ -62,7 +62,7 @@
     <protobuf.version>3.21.4</protobuf.version>
     <google.api-common.version>2.2.1</google.api-common.version>
     <google.common-protos.version>2.9.2</google.common-protos.version>
-    <google.core.version>2.8.3</google.core.version>
+    <google.core.version>2.8.4</google.core.version>
     <google.auth.version>1.8.1</google.auth.version>
     <google.http-client.version>1.42.2</google.http-client.version>
     <google.oauth-client.version>1.34.1</google.oauth-client.version>