Avoid NullPointerExceptions in console output in tests

Prior to this commit, the following types of NullPointerExceptions were
overlooked in the console output.

java.lang.NullPointerException: Cannot invoke "org.junit.platform.console.tasks.ConsoleTestExecutor.execute(java.io.PrintWriter, java.util.Optional)" because the return value of "org.junit.platform.console.tasks.ConsoleTestExecutor$Factory.create(org.junit.platform.console.options.TestDiscoveryOptions, org.junit.platform.console.options.TestConsoleOutputOptions)" is null

Although the NullPointerExceptions did not cause the tests to fail,
this commit updates the tests to avoid them anyway.

platform-tests/src/test/java/org/junit/platform/console/ConsoleLauncherTests.java

@@ -34,17 +34,17 @@ class ConsoleLauncherTests {
 	@ParameterizedTest(name = "{0}")
 	@MethodSource("commandsWithEmptyOptionExitCodes")
 	void displayHelp(String command) {
-		var consoleLauncher = new ConsoleLauncher((__, ___) -> null, printSink, printSink);
+		var consoleLauncher = new ConsoleLauncher(ConsoleTestExecutor::new, printSink, printSink);
 		var exitCode = consoleLauncher.run(command, "--help").getExitCode();
 
 		assertEquals(0, exitCode);
-		assertThat(stringWriter.toString()).contains("--help");
+		assertThat(stringWriter.toString()).contains("--help", "--disable-banner", "--scan-classpath" /* ... */);
 	}
 
 	@ParameterizedTest(name = "{0}")
 	@MethodSource("commandsWithEmptyOptionExitCodes")
 	void displayBanner(String command) {
-		var consoleLauncher = new ConsoleLauncher((__, ___) -> null, printSink, printSink);
+		var consoleLauncher = new ConsoleLauncher(ConsoleTestExecutor::new, printSink, printSink);
 		consoleLauncher.run(command);
 
 		assertThat(stringWriter.toString()).contains(
@@ -54,7 +54,7 @@ void displayBanner(String command) {
 	@ParameterizedTest(name = "{0}")
 	@MethodSource("commandsWithEmptyOptionExitCodes")
 	void disableBanner(String command, int expectedExitCode) {
-		var consoleLauncher = new ConsoleLauncher((__, ___) -> null, printSink, printSink);
+		var consoleLauncher = new ConsoleLauncher(ConsoleTestExecutor::new, printSink, printSink);
 		var exitCode = consoleLauncher.run(command, "--disable-banner").getExitCode();
 
 		assertEquals(expectedExitCode, exitCode);