Bump nexus-staging-maven-plugin from 1.6.7 to 1.6.8#15

dependabot-preview[bot] wants to merge 1 commit intomasterMutabilityDetector/MutabilityDetector4FindBugs:masterfrom

dependabot/maven/org.sonatype.plugins-nexus-staging-maven-plugin-1.6.8MutabilityDetector/MutabilityDetector4FindBugs:dependabot/maven/org.sonatype.plugins-nexus-staging-maven-plugin-1.6.8Copy head branch name to clipboard