deps: update flink.version to v1.16.1

Author: renovate-bot

pom.xml

@@ -12,7 +12,7 @@
   <artifactId>google-cloud-pubsublite-flink</artifactId>
   <version>0.1.0-SNAPSHOT</version>
   <properties>
-    <flink.version>1.15.0</flink.version>
+    <flink.version>1.16.1</flink.version>
     <pubsublite.version>${project.parent.version}</pubsublite.version>
   </properties>
   <build>