Decommission deprecated MD5HashValue and Crc32cChecksumValue types

These storage types were deprecated as part of https://github.com/googleapis/google-cloud-cpp/pull/16311. They should be removed 6 months after deprecation, roughly January 2027. Until that time several test.cc files have been updated to include `google/cloud/internal/disable_deprecation_warnings.inc`. When these types are removed, those deprecation includes should also be removed.

在仓库中搜索 MD5HashValue、Crc32cChecksumValue 和 google/cloud/internal/disable_deprecation_warnings.inc，以确定它们的定义、使用位置以及受影响的 test.cc 文件。确认六个月的弃用期已经结束，移除已弃用的类型及相关的警告抑制 include，然后运行相关测试以验证清理结果。

由索引模型根据 Issue 内容生成。