[V1]SupportsV0Only protocol for model definitions

[ywang96]

Repurposed from #13943 to add a SupportsV0Only protocol to models that are not compatible with vLLM V1 so that we can programmatically check the compatibility such as in #13726.

Doing this protocol instead of SupportsV1 also helps more easily track these models to migrate them to V1 as well as touching fewer files, since most models are now supported by V1 vLLM.

One caveat is that PixtralHF is currently not compatible with V1 but there's no way for us to differentiate it from Llava since transformers uses LlavaForConditionalGeneration definition for both models.

[github-actions]

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[mergify]

This pull request has merge conflicts that must be resolved before it can be
merged. Please rebase the PR, @ywang96.

https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork

[ywang96]

@robertgshaw2-redhat I turned on CI - feel free to review this whenever you have time.