fix: update dependency io.netty:netty-transport-native-epoll to v4.2.7.final (#559)

Author: renovate-bot

spannerlib/wrappers/spannerlib-java/pom.xml

@@ -64,7 +64,7 @@
     <dependency>
       <groupId>io.netty</groupId>
       <artifactId>netty-transport-native-epoll</artifactId>
-      <version>4.2.6.Final</version>
+      <version>4.2.7.Final</version>
     </dependency>
     <!-- Dependencies for using C library -->
     <dependency>