Remove pre-6.0 swift settings

feature/swift-testing

Author: roanutil

Package.swift

@@ -22,24 +22,21 @@ let package = Package(
     targets: [
         .target(
             name: "CoreDataRepository",
-            resources: [.process("Resources")],
-            swiftSettings: .swiftSix
+            resources: [.process("Resources")]
         ),
         .testTarget(
             name: "CoreDataRepositoryTests",
             dependencies: [
                 "CoreDataRepository",
                 .product(name: "CustomDump", package: "swift-custom-dump"),
                 "Internal",
-            ],
-            swiftSettings: .swiftSix
+            ]
         ),
         .target(
             name: "Internal",
             dependencies: [
                 "CoreDataRepository",
-            ],
-            swiftSettings: .swiftSix
+            ]
         ),
     ]
 )
@@ -66,18 +63,6 @@ extension [SupportedPlatform] {
     }
 }
 
-extension [SwiftSetting] {
-    static let swiftSix: Self = [
-        .enableUpcomingFeature("BareSlashRegexLiterals"),
-        .enableUpcomingFeature("ConciseMagicFile"),
-        .enableUpcomingFeature("DeprecateApplicationMain"),
-        .enableUpcomingFeature("DisableOutwardActorInference"),
-        .enableUpcomingFeature("ForwardTrailingClosures"),
-        .enableUpcomingFeature("ImportObjcForwardDeclarations"),
-        .enableUpcomingFeature("StrictConcurrency"),
-    ]
-}
-
 if ProcessInfo.benchmarkingEnabled {
     package.dependencies += [
         .package(