Update minimum macOS deployment target from 12.0 to 13.0 in Package.swift files

Agent-Logs-Url: https://github.com/github/CopilotForXcode/sessions/7096e011-d9d9-4710-b6aa-426ae95f1a7b

Co-authored-by: CroffZ <18088142+CroffZ@users.noreply.github.com>

Author: Copilot

Core/Package.swift

@@ -8,7 +8,7 @@ import PackageDescription
 
 let package = Package(
     name: "Core",
-    platforms: [.macOS(.v12)],
+    platforms: [.macOS(.v13)],
     products: [
         .library(
             name: "Service",

Tool/Package.swift

@@ -5,7 +5,7 @@ import PackageDescription
 
 let package = Package(
     name: "Tool",
-    platforms: [.macOS(.v12)],
+    platforms: [.macOS(.v13)],
     products: [
         .library(name: "XPCShared", targets: ["XPCShared"]),
         .library(name: "Terminal", targets: ["Terminal"]),