Move parallel test control to Jenkinsfile (#107)

Better to leave the control of parallel tests to the developer based on
their local machine configuration.  Use parallel tests on ci.jenkins.io
running one JVM tests process per core.

Jenkinsfile

@@ -1,12 +1,14 @@
 /* `buildPlugin` step provided by: https://github.com/jenkins-infra/pipeline-library */
 buildPlugin(
+  // Run a JVM per core in tests
+  forkCount: '1C',
   // Container agents start faster and are easier to administer
   useContainerAgent: true,
   // Show failures on all configurations
   failFast: false,
-  // Test Java 11 with a recent LTS, Java 17 even more recent
+  // Test Java 11 and Java 17
   configurations: [
-    [platform: 'linux',   jdk: '17', jenkins: '2.375.1'],
+    [platform: 'linux',   jdk: '17'],
     [platform: 'windows', jdk: '11']
   ]
 )

pom.xml

@@ -79,15 +79,6 @@
                     </execution>
                 </executions>
             </plugin>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-surefire-plugin</artifactId>
-                <configuration>
-                    <forkCount>1C</forkCount>
-                    <parallel>all</parallel>
-                    <useUnlimitedThreads>true</useUnlimitedThreads>
-                </configuration>
-            </plugin>
         </plugins>
     </build>