Fix CLIP _init_weights when a child module carries quantized weights (#47921)

* Fix _init_weights on CLIP models whose children carry quantized weights

`CLIPPreTrainedModel._init_weights` initializes the parameters of child modules by
name (`module.q_proj.weight`, `module.fc1.weight`, ...). A quantized checkpoint
replaces `weight` on those children with packed tensors -- `weight_packed` for
compressed-tensors, `qweight` for GPTQ/AWQ -- so loading one raises
`AttributeError: 'Linear' object has no attribute 'weight'` from the init pass that
`from_pretrained` runs for the keys that are missing from the checkpoint.

Route every child-weight initialization through a helper that skips a child that has
no `weight`, mirroring the guard the generic `PreTrainedModel._init_weights` already
applies to `nn.Linear`. Initialization of a non-quantized model is unchanged.

MetaCLIP-2 inlines this method through modular, so its modeling file is regenerated.

* Update src/transformers/models/clip/modeling_clip.py

* Update src/transformers/models/metaclip_2/modeling_metaclip_2.py

* Apply ruff format to the edited docstring and regenerate MetaCLIP-2

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Co-authored-by: Matt <Rocketknight1@users.noreply.github.com>