fix(systeminfo): Remove CPU count and enhance frequency logic

[electricface]

• Removed code related to CPU count retrieval; now consistently returns CPU model information without quantity
• Modified the Processor string to append frequency information, preventing duplicate frequency entries
• Updated relevant test cases by removing assertions for CPU count and verifying correct frequency appending

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fix(systeminfo): 删除CPU计数并增加频率补充逻辑

• 移除获取CPU数量相关代码，统一返回无数量的CPU型号信息
• 修改Processor字符串补充频率的实现，避免重复添加频率信息
• 更新相关测试用例，去除对CPU数量的断言，验证频率补充正确
  PMS: BUG-274991
  Influence: 控制中心->系统->关于本机->处理器