Enable strict concurrency checking

BUILD

@@ -73,7 +73,7 @@ swift_library(
     name = "SwiftLintCore",
     package_name = "SwiftLint",
     srcs = glob(["Source/SwiftLintCore/**/*.swift"]),
-    copts = copts,  # TODO: strict_concurrency_copts
+    copts = copts + strict_concurrency_copts,
     module_name = "SwiftLintCore",
     plugins = select({
         ":universal_tools_config": [":SwiftLintCoreMacros"],

Package.swift

@@ -87,7 +87,7 @@ let package = Package(
                 .product(name: "Yams", package: "Yams"),
                 "SwiftLintCoreMacros",
             ],
-            swiftSettings: swiftFeatures
+            swiftSettings: swiftFeatures + strictConcurrency
         ),
         .target(
             name: "SwiftLintBuiltInRules",