Prevent treating warnings as errors from conflicting in consuming packages (#71)

Author: dfed

Package.swift

@@ -25,15 +25,13 @@ let package = Package(
 			dependencies: [],
 			swiftSettings: [
 				.swiftLanguageMode(.v6),
-				.treatAllWarnings(as: .error),
 			],
 		),
 		.testTarget(
 			name: "AsyncQueueTests",
 			dependencies: ["AsyncQueue"],
 			swiftSettings: [
 				.swiftLanguageMode(.v6),
-				.treatAllWarnings(as: .error),
 			],
 		),
 	],