fix(ci): queue staging deployments

[ailuckly]

Do not cancel an in-progress staging deployment when a newer develop push or manual rerun starts.

This prevents GitHub Actions from terminating long remote Docker/Maven builds with 'The operation was canceled'.

Verification: git diff --check; ruby YAML.load_file('.github/workflows/cd-staging.yml')

📌 变更内容

• 如:新增用户登录 API
• 如:修复登录失败时错误提示

✅ 测试验证

• 本地运行通过
• 自测通过
• CI 流水线通过

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PR 提交规范提醒：

• 确保提交主题信息符合约定式提交规范 (feat/fix/docs/style/refactor/test/chore)
• 确保代码已经通过本地测试
• 确保没有提交敏感信息(密码、密钥等)

[Copilot]

Pull request overview

Adjusts the staging CD workflow’s concurrency behavior so newer runs no longer cancel an in-progress staging deployment, preventing long remote Docker/Maven builds from being terminated mid-flight.

Changes:

• Disable cancel-in-progress for the staging-deploy concurrency group so runs queue instead of canceling active deployments.

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