[LoRA] Handle DoRA better

[sayakpaul]

What does this PR do?

Our support for loading community DoRA checkpoints is currently broken. See KohakuBlueleaf/LyCORIS#216.

So, this PR:

1. Detects if a state dict has dora_scale present. Upon detection, it logs a warning about the incompatibility and filters the state dict so that it doesn't have the dora_scale keys.
2. Adjust the tests accordingly.

Once Ben gives a go ahead I will request for a review from Yiyi.

[HuggingFaceDocBuilderDev]

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[BenjaminBossan]

Yes, I agree it's better not to load these DoRA weights, as we now pretty much agree with Kohaku that their DoRA implementation is using the other axis.

Just a nit, the unit test could check for the new warning message.