build(deps): update dependency org.sonatype.plugins:nexus-staging-maven-plugin to v1.6.13 (googleapis#1638)

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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` -> `1.6.13` | [![age](https://badges.renovateapi.com/packages/maven/org.sonatype.plugins:nexus-staging-maven-plugin/1.6.13/age-slim)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://badges.renovateapi.com/packages/maven/org.sonatype.plugins:nexus-staging-maven-plugin/1.6.13/adoption-slim)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://badges.renovateapi.com/packages/maven/org.sonatype.plugins:nexus-staging-maven-plugin/1.6.13/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/1.6.13/confidence-slim/1.6.8)](https://docs.renovatebot.com/merge-confidence/) |

---

### Release Notes

<details>
<summary>sonatype/nexus-maven-plugins</summary>

### [`v1.6.13`](https://togithub.com/sonatype/nexus-maven-plugins/compare/release-1.6.12...release-1.6.13)

[Compare Source](https://togithub.com/sonatype/nexus-maven-plugins/compare/release-1.6.12...release-1.6.13)

### [`v1.6.12`](https://togithub.com/sonatype/nexus-maven-plugins/compare/release-1.6.11...release-1.6.12)

[Compare Source](https://togithub.com/sonatype/nexus-maven-plugins/compare/release-1.6.11...release-1.6.12)

### [`v1.6.11`](https://togithub.com/sonatype/nexus-maven-plugins/compare/release-1.6.10...release-1.6.11)

[Compare Source](https://togithub.com/sonatype/nexus-maven-plugins/compare/release-1.6.10...release-1.6.11)

### [`v1.6.10`](https://togithub.com/sonatype/nexus-maven-plugins/compare/release-1.6.9...release-1.6.10)

[Compare Source](https://togithub.com/sonatype/nexus-maven-plugins/compare/release-1.6.9...release-1.6.10)

</details>

---

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Author: renovate-bot

google-http-client-bom/pom.xml

@@ -117,7 +117,7 @@
       <plugin>
         <groupId>org.sonatype.plugins</groupId>
         <artifactId>nexus-staging-maven-plugin</artifactId>
-        <version>1.6.8</version>
+        <version>1.6.13</version>
         <extensions>true</extensions>
         <configuration>
           <serverId>sonatype-nexus-staging</serverId>

pom.xml

@@ -262,7 +262,7 @@
         <plugin>
           <groupId>org.sonatype.plugins</groupId>
           <artifactId>nexus-staging-maven-plugin</artifactId>
-          <version>1.6.8</version>
+          <version>1.6.13</version>
           <extensions>true</extensions>
           <configuration>
             <serverId>ossrh</serverId>

samples/pom.xml

@@ -46,7 +46,7 @@
       <plugin>
         <groupId>org.sonatype.plugins</groupId>
         <artifactId>nexus-staging-maven-plugin</artifactId>
-        <version>1.6.8</version>
+        <version>1.6.13</version>
         <configuration>
           <skipNexusStagingDeployMojo>true</skipNexusStagingDeployMojo>
         </configuration>