[Feature]: support layer size undividable by pp size in pipeline parallel inference

[youkaichao]

🚀 The feature, motivation and pitch

tracking the issue here

Alternatives

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Additional context

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[youkaichao]

first step: merge init_device into worker.__init__, before we create the model runner and cache engine, so that they can know the pp rank.

initialize distributed environment has complicated interference with spec decode. the temporary solution is to store the rank in the parallel config.