allow explicit tokenizer & text_encoder in unload_textual_inversion

[H3zi]

What does this PR do?

Fixes #6974

Currently, unload_textual_inversion only performs unload to tokenizer & text_encoder, originally designed for SD pipelines but doesn't support SDXL, which also uses tokenizer_2 & text_encoder_2.

By allowing passing explicitly the tokenizer & text_encoder to unload textual inversion modules (just like it allows in the load_textual_inversion function) we can support fully unload in SDXL pipelines as well.

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Who can review?

@sayakpaul @linoytsaban

[sayakpaul]

Hi,

Thanks for your PR. Could you also add an example snippet that shows the usage?

@yiyixuxu WDYT?

[HuggingFaceDocBuilderDev]

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[H3zi]

@sayakpaul Ive added a snippet based on the example demonstrated here by @linoytsaban, I hope it's OK.

[yiyixuxu]

cc @fabiorigano can you take a look here?

[fabiorigano]

thanks @yiyixuxu for adding me here

looks good to me. I left a few nits

[fabiorigano]

LGTM!