restore minimum maven version to 3.6.3

Author: hauner

pom.xml

@@ -38,7 +38,7 @@
     </scm>
 
     <prerequisites>
-        <maven>3.9.6</maven>
+        <maven>3.6.3</maven>
     </prerequisites>
 
     <properties>
@@ -63,21 +63,21 @@
             <!-- plugin interfaces and base classes -->
             <groupId>org.apache.maven</groupId>
             <artifactId>maven-plugin-api</artifactId>
-            <version>3.9.2</version>
+            <version>3.6.3</version>
             <scope>provided</scope>
         </dependency>
         <dependency>
             <!-- needed when injecting the Maven Project into a plugin  -->
             <groupId>org.apache.maven</groupId>
             <artifactId>maven-core</artifactId>
-            <version>3.9.2</version>
+            <version>3.6.3</version>
             <scope>provided</scope>
         </dependency>
         <dependency>
             <!-- annotations used to describe the plugin meta-data -->
             <groupId>org.apache.maven.plugin-tools</groupId>
             <artifactId>maven-plugin-annotations</artifactId>
-            <version>3.9.0</version>
+            <version>3.6.2</version>
             <scope>provided</scope>
         </dependency>
         <dependency>