removed reference to local.yml as it's never used and passing server_key

Dockerfile

@@ -32,12 +32,9 @@ FROM --platform=linux/arm64 heroiclabs/nakama:3.21.0 AS nakama
 # Copy plugin from builder stage
 COPY --from=plugin_builder /workspace/build/main.so /nakama/data/modules/main.so
 
-# Copy Nakama config
-COPY local.yml /nakama/data/local.yml
-
 # Default Nakama startup (runs migrations + server)
 ENTRYPOINT [
   "/bin/sh", "-ecx", "\
   /nakama/nakama migrate up --database.address \"$DB_ADDR\" && \
-  exec /nakama/nakama --config /nakama/data/local.yml --database.address \"$DB_ADDR\""
+  exec /nakama/nakama --database.address \"$DB_ADDR\" --socket.server_key=\"$SERVER_KEY\""
 ]