fix: remove duplicated code in TemporalBasicTransformerBlock.

[AsakusaRinne]

What does this PR do?

Fixes the duplication of the layernorm definition in TemporalBasicTransformerBlock.

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Review

@sayakpaul @yiyixuxu @DN6 I wonder if you'd like to review it though it's just a simple fix. :)

[sayakpaul]

Thanks!

[HuggingFaceDocBuilderDev]

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[AsakusaRinne]

Seems that the ci needs approval, could you please help?

[sayakpaul]

Please ping me once the CI workflow is complete. Will merge :)

[AsakusaRinne]

@sayakpaul All the ci has passed. :)