minimalMavenBuildVersion should not be overriding by mavenVersion

minimalMavenBuildVersion is used for build
mavenVersion is used for Maven Api version

We can build by newer version than is used as dependencies

pom.xml

@@ -197,8 +197,8 @@
     <minimalJavaBuildVersion>${mojo.java.target}</minimalJavaBuildVersion>
     <recommendedJavaBuildVersion>${minimalJavaBuildVersion}</recommendedJavaBuildVersion>
 
-    <mavenVersion>3.6.3</mavenVersion>
-    <minimalMavenBuildVersion>${mavenVersion}</minimalMavenBuildVersion>
+    <minimalMavenBuildVersion>3.6.3</minimalMavenBuildVersion>
+    <mavenVersion>${minimalMavenBuildVersion}</mavenVersion>
 
     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
     <!-- NOTE: We deliberately do not set maven.test.redirectTestOutputToFile here to workaround MNG-1992 -->