build(deps): update dependency org.sonatype.plugins:nexus-staging-maven-plugin to v1.6.9 (#526)

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This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| [org.sonatype.plugins:nexus-staging-maven-plugin](http://www.sonatype.com/) ([source](https://togithub.com/sonatype/nexus-maven-plugins)) | `1.6.8` -> `1.6.9` | [![age](https://badges.renovateapi.com/packages/maven/org.sonatype.plugins:nexus-staging-maven-plugin/1.6.9/age-slim)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://badges.renovateapi.com/packages/maven/org.sonatype.plugins:nexus-staging-maven-plugin/1.6.9/adoption-slim)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://badges.renovateapi.com/packages/maven/org.sonatype.plugins:nexus-staging-maven-plugin/1.6.9/compatibility-slim/1.6.8)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://badges.renovateapi.com/packages/maven/org.sonatype.plugins:nexus-staging-maven-plugin/1.6.9/confidence-slim/1.6.8)](https://docs.renovatebot.com/merge-confidence/) |

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Author: renovate-bot

notification/pom.xml

@@ -46,7 +46,7 @@
       <plugin>
         <groupId>org.sonatype.plugins</groupId>
         <artifactId>nexus-staging-maven-plugin</artifactId>
-        <version>1.6.8</version>
+        <version>1.6.9</version>
         <configuration>
           <skipNexusStagingDeployMojo>true</skipNexusStagingDeployMojo>
         </configuration>