Bump nexus-staging-maven-plugin from 1.6.3 to 1.6.8 (#258)

Bumps nexus-staging-maven-plugin from 1.6.3 to 1.6.8.

---
updated-dependencies:
- dependency-name: org.sonatype.plugins:nexus-staging-maven-plugin
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

pom.xml

@@ -287,7 +287,7 @@
                     <plugin>
                         <groupId>org.sonatype.plugins</groupId>
                         <artifactId>nexus-staging-maven-plugin</artifactId>
-                        <version>1.6.3</version>
+                        <version>1.6.8</version>
                         <extensions>true</extensions>
                         <configuration>
                             <serverId>sonatype-nexus-staging</serverId>