Revert maven GPG plugin update

Pinentry mode appears to now fail upon building.

Revert "Merge pull request #120 from ascopes/dependabot/maven/main/org.apache.maven.plugins-maven-gpg-plugin-3.2.0"

This reverts commit 12e1b9d, reversing
changes made to 4806bef.

pom.xml

@@ -111,7 +111,6 @@
     <license-maven-plugin.version>4.3</license-maven-plugin.version>
     <maven-checkstyle-plugin.version>3.3.1</maven-checkstyle-plugin.version>
     <maven-compiler-plugin.version>3.12.1</maven-compiler-plugin.version>
-    <maven-gpg-plugin.version>3.2.0</maven-gpg-plugin.version>
     <maven-invoker-plugin.version>3.6.0</maven-invoker-plugin.version>
     <maven-jar-plugin.version>3.3.0</maven-jar-plugin.version>
     <maven-javadoc-plugin.version>3.6.3</maven-javadoc-plugin.version>
@@ -124,6 +123,10 @@
     <maven-surefire-plugin.version>3.2.5</maven-surefire-plugin.version>
     <sisu-maven-plugin.version>0.3.5</sisu-maven-plugin.version>
 
+    <!-- Do not update this version. 3.2.0 appears to break pinentry mode -->
+    <maven-gpg-plugin.version>3.1.0</maven-gpg-plugin.version>
+
+
     <!-- Plugin dependencies -->
     <checkstyle.version>10.14.1</checkstyle.version>
     <maven-surefire-junit5-tree-reporter.version>1.2.1</maven-surefire-junit5-tree-reporter.version>