accelerate

6b6d0ec6 - fix(state): make MLU backend part of the _prepare_backend elif chain (#4057)

fix(state): make MLU backend part of the _prepare_backend elif chain (#4057) `is_mlu_available()` was checked with a standalone `if` followed by a separate `if is_sdaa_available()` chain, so on an MLU host the cncl/MULTI_MLU selection could be silently overwritten by a later branch (e.g. cuda) instead of short-circuiting. Switch the second `if` to `elif` so all accelerator backends form a single mutually-exclusive chain, matching default_device. Fixes #4055