[BugFix] Exit if neither modern nor legacy wheel dir not found

[SigureMo]

Motivation

💡 If this PR is a Cherry Pick, the PR title needs to follow the format by adding the [Cherry-Pick] label at the very beginning and appending the original PR ID at the end. For example, [Cherry-Pick][CI] Add check trigger and logic(#5191)

💡 如若此PR是Cherry Pick，PR标题需遵循格式，在最开始加上[Cherry-Pick]标签，以及最后面加上原PR ID，例如[Cherry-Pick][CI] Add check trigger and logic(#5191)

#5156 实现的根据 modern or legacy 目录结构来判断要以何种方式 copy 的逻辑在某些情况可能走到第三个分支，此时就会将根目录里的内容 copy 到 ops 目录，该问题可能是由于某些奇怪的缓存导致的，因为更新后无法复现所以在第三个分支退出以避免 copy 根目录导致的严重问题

Modifications

在 GPU/XPU 的目录结构判断逻辑的第三个分支直接退出，并添加清理构建目录的提示

Usage or Command

bash build.sh

Accuracy Tests

Checklist

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  • Tag list: [[FDConfig],[APIServer],[Engine], [Scheduler], [PD Disaggregation], [Executor], [Graph Optimization], [Speculative Decoding], [RL], [Models], [Quantization], [Loader], [OP], [KVCache], [DataProcessor], [BugFix], [Docs], [CI], [Optimization], [Feature], [Benchmark], [Others], [XPU], [HPU], [GCU], [DCU], [Iluvatar], [Metax]]
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[Copilot]

Pull request overview

This PR fixes a critical bug where the build script could incorrectly copy root directory contents to the ops directory when neither modern nor legacy wheel directory structures are found. The fix adds proper error handling to exit early with helpful messages.

• Adds exit 1 to prevent dangerous root directory copying when directory structure detection fails
• Provides informative error messages suggesting to clean build directories when compilation fails
• Applied consistently to both GPU ops (build.sh) and XPU ops (custom_ops/xpu_ops/build.sh)

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
build.sh	Adds exit and cleanup guidance when GPU ops directory structure is not found
custom_ops/xpu_ops/build.sh	Adds exit and cleanup guidance when XPU ops directory structure is not found

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
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Additional details and impacted files

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