[CI/Test Fix] Fix CP tests on Blackwell

[LucasWilkinson]

FIX: #28400

[gemini-code-assist]

Code Review

This pull request adds conditional skips to context parallelism tests based on GPU compute capability, which is a good approach to handle hardware-specific features in CI. The logic for deepseek-ai/DeepSeek-V2-Lite-Chat seems correct. However, the condition for bigcode/gpt_bigcode-santacoder is overly restrictive and could prevent tests from running on future GPU architectures. I've provided a suggestion to make this more forward-compatible.

[robertgshaw2-redhat]

Can you create a "good first issue" asking for someone to contribute a better error message if the attn backend is incompatible?

I know we have ongoing work to add more backends

[LucasWilkinson]

Can you create a "good first issue" asking for someone to contribute a better error message if the attn backend is incompatible?

I know we have ongoing work to add more backends

I made an issue (#28407) but Im scared we will only get a minor improvement in the error message for alot of complexity (basically maintaining an independent list backends that support DCP); i think it may be best to wait for #24794 which should be landing shortly

[robertgshaw2-redhat]

shoot, didnt mean to hit that button 🤦