Update protobuf monorepo from v3.25.5 to v3.25.6

Author: renovate[bot]

pom.xml

@@ -92,12 +92,12 @@
         <dependency>
             <groupId>com.google.protobuf</groupId>
             <artifactId>protobuf-java</artifactId>
-            <version>3.25.5</version>
+            <version>3.25.6</version>
         </dependency>
         <dependency>
             <groupId>com.google.protobuf</groupId>
             <artifactId>protobuf-java-util</artifactId>
-            <version>3.25.5</version>
+            <version>3.25.6</version>
         </dependency>
         <dependency>
             <groupId>org.entur</groupId>