Update LCMScheduler Inference Timesteps to be More Evenly Spaced (#5836)
* Change LCMScheduler.set_timesteps to pick more evenly spaced inference timesteps.
* Change inference_indices implementation to better match previous behavior.
* Add num_inference_steps=26 test case to test_inference_steps.
* run CI
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Co-authored-by: patil-suraj <surajp815@gmail.com>