fix warning message for SpringExtension

Author: xvik

src/main/java/ru/vyarus/spock/jupiter/JunitExtensionSupport.java

@@ -228,7 +228,7 @@ private List<Class<? extends Extension>> getIgnoredExtensions(final IgnoreJunitE
         // spock's mocking abilities
         try {
             Class.forName("org.spockframework.spring.SpringExtension");
-            System.out.println("[spock-junit6] WARN: Spring junit extension disabled (org.springframework.test"
+            System.out.println("[spock-junit5] WARN: Spring junit extension disabled (org.springframework.test"
                     + ".context.junit.jupiter.SpringExtension) because spock-spring detected and so it will handle "
                     + "spring context initialization (all other junit extensions will work). If you want to run "
                     + "spring as junit extension, use spock-core only (without spock-spring).");

src/main/java/ru/vyarus/spock/jupiter/engine/context/EngineContext.java

@@ -5,7 +5,7 @@
 import ru.vyarus.spock.jupiter.engine.ExtensionRegistry;
 
 import java.lang.reflect.Method;
-import java.util.List;
+import java.util.Collections;
 import java.util.Optional;
 
 /**
@@ -22,7 +22,7 @@
 public class EngineContext extends AbstractContext {
 
   public EngineContext() {
-    super(null, new ExtensionRegistry(null, List.of()), null, null);
+    super(null, new ExtensionRegistry(null, Collections.emptyList()), null, null);
   }
 
   @Override