fix(trainer): init self.generate_sweep_kwarg at self.__init__

[mymusise]

If we do trainer.evaluate() before trainer.learn(), it will rasie AttributeError like:

│ ❱ 310 │   │   if self.generate_sweep_kwarg is not None:                                          │
│   311 │   │   │   gen_sweep_arg, gen_sweep_values = self.generate_sweep_kwarg                    │
│   312 │   │   else:                                                                              │
│   313 │   │   │   gen_sweep_values = [None]                                                      │
╰──────────────────────────────────────────────────────────────────────────────────────────────────╯
AttributeError: 'AccelerateILQLTrainer' object has no attribute 'generate_sweep_kwarg'

so, I think it's better to initialize generate_sweep_kwarg with the initialization of the trainer

And the same with self.nth_evaluation

[maxreciprocate]

Makes sense! Maybe also let's move the block that initializes generate_sweep_kwarg along into trainer's initialization?

[mymusise]

Makes sense! Maybe also let's move the block that initializes generate_sweep_kwarg along into trainer's initialization?

Makes sense! The initialization of generate_sweep_kwarg depends only on trainer.config.

[maxreciprocate]

LGTM!