[Bugfix] Fix Cosmos3 FP8 tensor parallelism

[yzhautouskay]

What does this PR do?

Skip ModelOpt quantizer children during row-wise sharding to fix:
AttributeError: 'TensorQuantizer' object has no attribute 'weight'

Tested with nvidia/Cosmos3-Super, revision fp8, using mixed W8A16/W8A8 inference on GB200: TP2/CP2 and TP4/CP1, 720p, 189 frames, 35 steps.

tp_fp8.mp4

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[github-actions]

Hi @yzhautouskay, thanks for the PR! It does not appear to link an issue it fixes. If this PR addresses an existing issue, please add a closing keyword (e.g. Fixes #1234) to the PR description so the issue is linked. See the contribution guide for more details. If this PR intentionally does not fix a tracked issue, a maintainer can add the no-issue-needed label to silence this reminder.

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[yiyixuxu]

thanks

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