Bump maven-gpg-plugin from 1.5 to 1.6

Bumps maven-gpg-plugin from 1.5 to 1.6.

Author: dependabot-preview[bot]

pom.xml

@@ -111,7 +111,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-gpg-plugin</artifactId>
-                <version>1.5</version>
+                <version>1.6</version>
                 <executions>
                     <execution>
                         <id>sign-artifacts</id>
@@ -199,7 +199,7 @@
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-gpg-plugin</artifactId>
-                    <version>1.5</version>
+                    <version>1.6</version>
                     <executions>
                         <execution>
                             <id>sign-artifacts</id>