add post_version hook to regenerate Maven lockfile on release

Author: rauchy

.codegen.json

@@ -12,6 +12,7 @@
   "toolchain": {
     "require": ["mvn", "java"],
     "setup": ["bash scripts/cleanup-services.sh"],
-    "post_generate": ["mvn spotless:apply","mvn --errors clean test"]
+    "post_generate": ["mvn spotless:apply","mvn --errors clean test"],
+    "post_version": ["mvn io.github.chains-project:maven-lockfile:5.5.2:generate"]
   }
 }