tests : fix ggml init (#29554)

* tests : init ggml for test-recurrent-state-rollback

* cont : same for test-save-load-state

* cont : add to test-state-restore-fragmented + add TODOs

src/llama.cpp

@@ -401,6 +401,7 @@ static struct llama_model * llama_model_load_from_file_impl(
             return nullptr;
         }
     }
+    // TODO: remove
     ggml_time_init();
 
     if (!params.vocab_only && ggml_backend_reg_count() == 0) {