Add --lora_alpha and metadata handling to train_dreambooth_lora_sd3.py

[arnav-roy]

What does this PR do?

Fixes#11730

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[arnav-roy]

@linoytsaban Please review

[linoytsaban]

thanks @arnav-roy! I see lora_alpha is missing from the text_encoder config, other than that I think we're good :)

diffusers/examples/dreambooth/train_dreambooth_lora_sd3.py

Lines 1283 to 1289 in cf127dd

	ifargs.train_text_encoder:
	text_lora_config=LoraConfig(
	r=args.rank,
	lora_alpha=args.rank,
	lora_dropout=args.lora_dropout,
	init_lora_weights="gaussian",
	target_modules=["q_proj", "k_proj", "v_proj", "out_proj"],

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[yiyixuxu]

@arnav-roy can you make the request change?

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. If you think this still needs to be addressed please comment on this thread.

Please note that issues that do not follow the contributing guidelines are likely to be ignored.