Refactor OpenTestReportGeneratingListener to work in native images

Fixes #3035.

Author: marcphilipp

documentation/src/docs/asciidoc/release-notes/release-notes-5.9.1.adoc

@@ -16,6 +16,8 @@ on GitHub.
 ==== Bug Fixes
 
 * `ReflectionSupport.findMethods(...)` now returns a distinct set of methods.
+* Execution in GraalVM native images no longer requires `--initialize-at-build-time` for
+  `OpenTestReportGeneratingListener`.
 
 ==== Deprecations and Breaking Changes
 

junit-platform-reporting/src/main/java/org/junit/platform/reporting/open/xml/OpenTestReportGeneratingListener.java

@@ -90,12 +90,6 @@ public class OpenTestReportGeneratingListener implements TestExecutionListener {
 	static final String ENABLED_PROPERTY_NAME = "junit.platform.reporting.open.xml.enabled";
 	static final String OUTPUT_DIR_PROPERTY_NAME = "junit.platform.reporting.output.dir";
 
-	private static final NamespaceRegistry NAMESPACE_REGISTRY = NamespaceRegistry.builder(Namespace.REPORTING_CORE) //
-			.add("e", Namespace.REPORTING_EVENTS) //
-			.add("java", Namespace.REPORTING_JAVA) //
-			.add("junit", JUnitFactory.NAMESPACE, "https://junit.org/junit5/schemas/open-test-reporting/junit-1.9.xsd") //
-			.build();
-
 	private final AtomicInteger idCounter = new AtomicInteger();
 	private final Map<UniqueId, String> inProgressIds = new ConcurrentHashMap<>();
 	private DocumentWriter<Events> eventsFileWriter = DocumentWriter.noop();
@@ -107,10 +101,16 @@ public OpenTestReportGeneratingListener() {
 	public void testPlanExecutionStarted(TestPlan testPlan) {
 		ConfigurationParameters config = testPlan.getConfigurationParameters();
 		if (isEnabled(config)) {
+			NamespaceRegistry namespaceRegistry = NamespaceRegistry.builder(Namespace.REPORTING_CORE) //
+					.add("e", Namespace.REPORTING_EVENTS) //
+					.add("java", Namespace.REPORTING_JAVA) //
+					.add("junit", JUnitFactory.NAMESPACE,
+						"https://junit.org/junit5/schemas/open-test-reporting/junit-1.9.xsd") //
+					.build();
 			Path eventsXml = OutputDir.create(config.get(OUTPUT_DIR_PROPERTY_NAME)) //
 					.createFile("junit-platform-events", "xml");
 			try {
-				eventsFileWriter = Events.createDocumentWriter(NAMESPACE_REGISTRY, eventsXml);
+				eventsFileWriter = Events.createDocumentWriter(namespaceRegistry, eventsXml);
 				reportInfrastructure();
 			}
 			catch (Exception e) {