add _cann_ops_custom gitignore

[zzzzwwjj]

What this PR does / why we need it?

add _cann_ops_custom dir to .gitignore

Does this PR introduce any user-facing change?

How was this patch tested?

• vLLM version: v0.11.2
• vLLM main: https://github.com/vllm-project/vllm/commit/v0.11.2

[gemini-code-assist]

Code Review

This pull request aims to add the _cann_ops_custom directory, which contains generated files, to .gitignore. While this is the correct intention, the current implementation ignores the entire directory, which conflicts with the presence of a .gitkeep file designed to keep the directory in the repository. My review provides a suggestion to correctly ignore the directory's contents while preserving the .gitkeep file, ensuring repository integrity for new clones.

[gemini-code-assist]

Ignoring the entire /vllm_ascend/_cann_ops_custom directory conflicts with the presence of the .gitkeep file within it. The purpose of .gitkeep is to ensure the directory is tracked in the repository, even when empty. If you ignore the parent directory, you cannot track any files inside it, including .gitkeep.

To correctly ignore the generated contents while keeping the directory and its .gitkeep file tracked, you should ignore all contents of the directory and then explicitly un-ignore the .gitkeep file.

/vllm_ascend/_cann_ops_custom/*
!/vllm_ascend/_cann_ops_custom/.gitkeep

[github-actions]

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