add WANDB_DISABLED for p-tuning as default

[panpan0000]

otherwise, it always prompt below human interaction , when running p-tuning script "bash train.sh"

>> Automatic Weights & Biases logging enabled, to disable set os.environ["WANDB_DISABLED"] = "true"
wandb: (1) Create a W&B account
wandb: (2) Use an existing W&B account
wandb: (3) Don't visualize my results
wandb: Enter your choice: 

so disable it by default

[nuaabuaa07]

在 train.sh中，顶部增加一行。export WANDB_DISABLED="true" 。其实就是增加一个环境变量。

[panpan0000]

默认关闭对新手更友好