refactor(package.swift): add macos version

- the build process requires a higher macos version according to the error in the autobuild 

error: the library 'FusionAuth' requires macos 10.13, but depends on the product 'SwiftLintBuildToolPlugin' which requires macos 12.0; consider changing the library 'FusionAuth' to require macos 12.0 or later, or the product 'SwiftLintBuildToolPlugin' to require macos 10.13 or earlier.

Author: Aaron-Ritter

Package.swift

@@ -6,6 +6,7 @@ import PackageDescription
 let package = Package(
     name: "FusionAuth",
     platforms: [
+        .macOS(.v12),
         .iOS(.v15)
     ],
     products: [