Bump org.apache.maven.plugins:maven-gpg-plugin from 3.2.7 to 3.2.8 (#656)

Bumps [org.apache.maven.plugins:maven-gpg-plugin](https://github.com/apache/maven-gpg-plugin) from 3.2.7 to 3.2.8.
- [Release notes](https://github.com/apache/maven-gpg-plugin/releases)
- [Commits](apache/maven-gpg-plugin@maven-gpg-plugin-3.2.7...maven-gpg-plugin-3.2.8)

---
updated-dependencies:
- dependency-name: org.apache.maven.plugins:maven-gpg-plugin
  dependency-version: 3.2.8
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

sslcontext-kickstart-bom/pom.xml

@@ -51,7 +51,7 @@
 
     <properties>
         <version.maven-compiler-plugin>3.14.0</version.maven-compiler-plugin>
-        <version.maven-gpg-plugin>3.2.7</version.maven-gpg-plugin>
+        <version.maven-gpg-plugin>3.2.8</version.maven-gpg-plugin>
         <version.maven-release-plugin>3.1.1</version.maven-release-plugin>
         <version.nexus-staging-maven-plugin>1.7.0</version.nexus-staging-maven-plugin>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>