Update dependency org.codehaus.mojo:exec-maven-plugin to v3

Author: renovate[bot]

pom.xml

@@ -72,7 +72,7 @@
     <junit.version>5.14.2</junit.version>
 
     <!-- Maven plugin versions  -->
-    <maven-exec-plugin.version>1.6.0</maven-exec-plugin.version>
+    <maven-exec-plugin.version>3.6.3</maven-exec-plugin.version>
     <maven-surefire-plugin.version>2.22.2</maven-surefire-plugin.version>
     <maven-source-plugin.version>3.4.0</maven-source-plugin.version>
     <maven-javadoc-plugin.version>3.12.0</maven-javadoc-plugin.version>