Keep junit extensions in static fields (#12166)

instrumentation/aws-sdk/aws-sdk-2.2/library/src/test/java/io/opentelemetry/instrumentation/awssdk/v2_2/Aws2ClientNotRecordHttpErrorTest.java

@@ -12,7 +12,8 @@ import software.amazon.awssdk.core.client.config.ClientOverrideConfiguration;
 
 public class Aws2ClientNotRecordHttpErrorTest extends AbstractAws2ClientRecordHttpErrorTest {
   @RegisterExtension
-  public final LibraryInstrumentationExtension testing = LibraryInstrumentationExtension.create();
+  public static final LibraryInstrumentationExtension testing =
+      LibraryInstrumentationExtension.create();
 
   @Override
   public ClientOverrideConfiguration.Builder createOverrideConfigurationBuilder() {

instrumentation/rmi/javaagent/src/test/java/io/opentelemetry/javaagent/instrumentation/rmi/RmiTest.java

@@ -37,7 +37,7 @@ class RmiTest {
   private static Registry serverRegistry;
   private static Registry clientRegistry;
 
-  @RegisterExtension final AutoCleanupExtension autoCleanup = AutoCleanupExtension.create();
+  @RegisterExtension static final AutoCleanupExtension autoCleanup = AutoCleanupExtension.create();
 
   @BeforeAll
   static void setUp() throws Exception {

instrumentation/spring/spring-security-config-6.0/library/src/test/java/io/opentelemetry/instrumentation/spring/security/config/v6_0/EnduserAttributesCapturerTest.java

@@ -23,7 +23,8 @@ import org.springframework.security.web.authentication.preauth.PreAuthenticatedA
 
 public class EnduserAttributesCapturerTest {
 
-  @RegisterExtension InstrumentationExtension testing = LibraryInstrumentationExtension.create();
+  @RegisterExtension
+  static final InstrumentationExtension testing = LibraryInstrumentationExtension.create();
 
   @Test
   void nothingEnabled() {