Fix log replay of the Log4j 2 appender (#10243)

Author: jeanbisutti

instrumentation/log4j/log4j-appender-2.17/library/src/main/java/io/opentelemetry/instrumentation/log4j/appender/v2_17/OpenTelemetryAppender.java

@@ -157,9 +157,6 @@ public B setOpenTelemetry(OpenTelemetry openTelemetry) {
     @Override
     public OpenTelemetryAppender build() {
       OpenTelemetry openTelemetry = this.openTelemetry;
-      if (openTelemetry == null) {
-        openTelemetry = OpenTelemetry.noop();
-      }
       return new OpenTelemetryAppender(
           getName(),
           getLayout(),

instrumentation/log4j/log4j-appender-2.17/library/src/test/java/io/opentelemetry/instrumentation/log4j/appender/v2_17/LogReplayOpenTelemetryAppenderTest.java

@@ -14,6 +14,7 @@
 import java.util.List;
 import org.apache.logging.log4j.message.StringMapMessage;
 import org.apache.logging.log4j.message.StructuredDataMessage;
+import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
@@ -22,6 +23,10 @@ class LogReplayOpenTelemetryAppenderTest extends AbstractOpenTelemetryAppenderTe
   @BeforeEach
   void setup() {
     generalBeforeEachSetup();
+  }
+
+  @AfterEach
+  void resetOpenTelemetry() {
     OpenTelemetryAppender.install(null);
   }