chore(deps-dev): bump org.apache.maven:maven-compat (#374)

Author: dependabot[bot]

jsonschema-maven-plugin/pom.xml

@@ -20,7 +20,7 @@
     </prerequisites>
 
     <properties>
-        <maven.core.version>3.6.3</maven.core.version>
+        <maven.core.version>3.8.1</maven.core.version>
         <maven.testing.version>3.3.0</maven.testing.version>
         <maven.tools.version>3.6.0</maven.tools.version>
     </properties>