Remove unused Processor rpc service

PiperOrigin-RevId: 688488306

fleetspeak/src/server/grpcservice/proto/fleetspeak_grpcservice/grpcservice.proto

@@ -13,10 +13,3 @@ message Config {
       3;  // If set, a pool of trusted certificates will be read from this file
           // and used to authenticate the connection to target.
 }
-
-// Processor is the service that a target system must implement to
-// receive messages through a GRPCService based service.
-service Processor {
-  // Process accepts message and processes it.
-  rpc Process(fleetspeak.Message) returns (fleetspeak.EmptyMessage) {}
-}