[Bugfix] Reject matryoshka embedding dimensions above hidden size

[EazyReal]

Summary

For matryoshka embedding models without an explicit matryoshka_dimensions list, PoolingParams._set_default_parameters only checked dimensions >= 1. A dimensions value above the model's hidden size was then silently used to slice the embedding ([..., :d]), returning a hidden_size-length vector instead of rejecting the request. Add the upper-bound check (mirrors sglang's _validate_for_matryoshka_dim).

Test

tests/test_pooling_params.py: oversized dimensions for a matryoshka model (no dimensions list) now raises ValueError. Silently truncates on current main.

[github-actions]

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[noooop]

thanks!

[noooop]

Please do not submit any more code, as it will break the CI run.

[EazyReal]

@noooop Sounds good. Was removing some comments and doing some simplication. The logics should stay the same. Will not update code from here.