Do not prepare lr scheduler as it as the right number of steps
# What does this PR do?

Right now the LR scheduler is prepared by the Accelerate but it has a number of steps that already accounts for the number of processes. This results in the LR scheduler being stepp through num_processes too fast. This PR thus removes the lr_scheduler from the prepared objects.

Should fix #23986 
_The documentation is not available anymore as the PR was closed or merged._