Fix ControlNetModel.from_unet do not load add_embedding

[laksjdjf]

What does this PR do?

Recreate from #7173

Who can review?

@sayakpaul , @yiyixuxu

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.

[sayakpaul]

Let's fix the tests :)

[laksjdjf]

Let's fix the tests :)

@sayakpaul
I removed meaningless spaces for test.
Are there any other operations required?

[sayakpaul]

Looks good to me!

[laksjdjf]

@sayakpaul
Is this error relevant to this pr?

=========================== short test summary info ============================
FAILED tests/pipelines/unidiffuser/test_unidiffuser.py::UniDiffuserPipelineFastTests::test_attention_slicing_forward_pass - requests.exceptions.ReadTimeout: (ReadTimeoutError("HTTPSConnectionPool(host='huggingface.co', port=443): Read timed out. (read timeout=10)"), '(Request ID: 869e35f5-5627-4acf-9853-7187ce7d0656)')
==== 1 failed, 2193 passed, 989 skipped, 4415 warnings in 937.44s (0:15:37) ====

[sayakpaul]

It's not!