deps: update dependency com.google.cloud.tools:dependencies-parent to v1.5.2 (#875)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [com.google.cloud.tools:dependencies-parent](https://github.com/GoogleCloudPlatform/cloud-opensource-java) | patch | `1.5.1` -> `1.5.2` |

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### Release Notes

<details>
<summary>GoogleCloudPlatform/cloud-opensource-java</summary>

### [`v1.5.2`](https://github.com/GoogleCloudPlatform/cloud-opensource-java/blob/master/CHANGELOG.md#&#8203;152)

-   Linkage Checker enforcer rule works with other repositories than Maven Central.

</details>

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Author: renovate-bot

dashboard/pom.xml

@@ -6,7 +6,7 @@
   <parent>
     <groupId>com.google.cloud.tools</groupId>
     <artifactId>dependencies-parent</artifactId>
-    <version>1.5.1</version>
+    <version>1.5.2</version>
   </parent>
   <artifactId>google-cloud-bom-dashboard</artifactId>
   <version>0.0.1-SNAPSHOT</version>