Delete obsolete test code

We no longer register reflection run-time hints for the SpringExtension
since that is covered by the JupiterConfigProvider in the GraalVM Native
Build Tools project.

spring-test/src/test/java/org/springframework/test/context/aot/samples/basic/BasicSpringJupiterTests.java

@@ -17,8 +17,6 @@
 package org.springframework.test.context.aot.samples.basic;
 
 import org.junit.jupiter.api.Nested;
-import org.junit.jupiter.api.extension.ExtendWith;
-import org.junit.jupiter.api.extension.Extension;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Value;
@@ -26,7 +24,6 @@ import org.springframework.context.ApplicationContext;
 import org.springframework.test.context.ActiveProfiles;
 import org.springframework.test.context.TestExecutionListeners;
 import org.springframework.test.context.TestPropertySource;
-import org.springframework.test.context.aot.samples.basic.BasicSpringJupiterTests.DummyExtension;
 import org.springframework.test.context.aot.samples.basic.BasicSpringJupiterTests.DummyTestExecutionListener;
 import org.springframework.test.context.aot.samples.common.MessageService;
 import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
@@ -39,9 +36,6 @@ import static org.springframework.test.context.TestExecutionListeners.MergeMode.
  * @author Sam Brannen
  * @since 6.0
  */
-// Register an extension other than the SpringExtension to verify proper lookups
-// for repeated annotations.
-@ExtendWith(DummyExtension.class)
 @SpringJUnitConfig(BasicTestConfiguration.class)
 @TestExecutionListeners(listeners = DummyTestExecutionListener.class, mergeMode = MERGE_WITH_DEFAULTS)
 @TestPropertySource(properties = "test.engine = jupiter")
@@ -73,9 +67,6 @@ public class BasicSpringJupiterTests {
 
 	}
 
-	static class DummyExtension implements Extension {
-	}
-
 	public static class DummyTestExecutionListener extends AbstractTestExecutionListener {
 	}