Upgrade to Log4j2 2.23.0

Closes gh-39713

Author: wilkinsona

spring-boot-project/spring-boot-dependencies/build.gradle

@@ -842,7 +842,7 @@ bom {
 			]
 		}
 	}
-	library("Log4j2", "2.22.1") {
+	library("Log4j2", "2.23.0") {
 		group("org.apache.logging.log4j") {
 			imports = [
 				"log4j-bom"

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/logging/log4j2/CorrelationIdConverterTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2023 the original author or authors.
+ * Copyright 2012-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -57,7 +57,7 @@ static class TestLogEvent extends AbstractLogEvent {
 		@Override
 		public ReadOnlyStringMap getContextData() {
 			return new JdkMapAdapterStringMap(
-					Map.of("traceId", "01234567890123456789012345678901", "spanId", "0123456789012345"));
+					Map.of("traceId", "01234567890123456789012345678901", "spanId", "0123456789012345"), true);
 		}
 
 	}