Fix Copying Mechanism typo/bug

[tolgacangoz]

What does this PR do?

"# copied from ..."s don't trigger the Copying Mechanism; thus they are capitalized. Also, decorators need to be at the top of "# Copied from ..."s.

The _convert_to_karras function in scheduling_dpmsolver_sde.py and scheduling_lms_discrete.py also has this typo (?). But, it is included in a TODO task in the comments where they copied from, thus leaving them as are.

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• [x] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
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• [ ] Did you write any new necessary tests?

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