chore(deps): update dependency org.apache.logging.log4j:log4j-slf4j2-impl to v2.21.0 (#501)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

providers/go-feature-flag/pom.xml

@@ -71,7 +71,7 @@
         <dependency>
             <groupId>org.apache.logging.log4j</groupId>
             <artifactId>log4j-slf4j2-impl</artifactId>
-            <version>2.20.0</version>
+            <version>2.21.0</version>
             <scope>test</scope>
         </dependency>
 

providers/unleash/pom.xml

@@ -39,7 +39,7 @@
         <dependency>
             <groupId>org.apache.logging.log4j</groupId>
             <artifactId>log4j-slf4j2-impl</artifactId>
-            <version>2.20.0</version>
+            <version>2.21.0</version>
             <scope>test</scope>
         </dependency>