[chore] add triton-ascend to requirements.txt

[wxh571001500]

What this PR does / why we need it?

Previously, when adapting vllm-ascend to models such as Qwen-Next, users needed to install the triton_ascend dependency separately. Therefore, to improve usability, the dependency is now included in requirements.txt and installed along with vllm-ascend.

Does this PR introduce any user-facing change?

nope

How was this patch tested?

After installing vllm-ascend, we can use “pip list” to observe that triton-ascend is also installed synchronously.

[github-actions]

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[gemini-code-assist]

Code Review

This pull request adds triton-ascend as a dependency in requirements.txt. However, the corresponding pyproject.toml file was not updated. To maintain consistency and prevent potential build issues, this dependency should also be added to pyproject.toml's build-system.requires list, as is the convention in this repository.