Update Log4J version to 2.23.1

Author: deki

aws-lambda-java-log4j2/pom.xml

@@ -34,7 +34,7 @@
     <properties>
         <maven.compiler.source>1.8</maven.compiler.source>
         <maven.compiler.target>1.8</maven.compiler.target>
-        <log4j.version>2.21.1</log4j.version>
+        <log4j.version>2.23.1</log4j.version>
     </properties>
 
     <distributionManagement>