Package.swift: fix deprecation warnings (package(name:url:from:), revision)

When resolving or building with a recent Swift toolchain, `Package.swift` triggers deprecation warnings:

- `package(name:url:from:)` is deprecated: use `package(url:from:)` instead
- `package(name:url:_:)` with `.revision` / `revision` is deprecated: use specific requirement APIs

Please update the dependency declarations in `Package.swift` to the non-deprecated SPM APIs so the package builds without warnings.

Seen on Swift 6 / Xcode 16+ with GoogleSignIn-iOS 9.1.0.

检查 Package.swift 中的依赖声明，重点关注 issue 中所描述的已弃用的 package(name:url:from:) 和 revision 形式。将它们更新为对应的未弃用 Swift Package Manager API，然后使用 Swift 6/Xcode 16+ 执行 resolve 或 build，并确认警告已消失。

由索引模型根据 Issue 内容生成。