Update dependency org.codehaus.mojo:flatten-maven-plugin to v1.6.0
diff --git a/jgvariant-parent/pom.xml b/jgvariant-parent/pom.xml
index 5fd3f64..a07a388 100644
--- a/jgvariant-parent/pom.xml
+++ b/jgvariant-parent/pom.xml
@@ -58,7 +58,7 @@
     <compiler-plugin.version>3.12.1</compiler-plugin.version>
     <exec-plugin.version>3.1.1</exec-plugin.version>
     <failsafe-plugin.version>${surefire-plugin.version}</failsafe-plugin.version>
-    <flatten-plugin.version>1.5.0</flatten-plugin.version>
+    <flatten-plugin.version>1.6.0</flatten-plugin.version>
     <jar-plugin.version>3.3.0</jar-plugin.version>
     <jpackage-plugin.version>0.1.5</jpackage-plugin.version>
     <maven-scm-plugin.version>2.0.1</maven-scm-plugin.version>