Updated license header

Author: btoms20

Package.swift

@@ -1,5 +1,17 @@
-// swift-tools-version:5.4
-// The swift-tools-version declares the minimum version of Swift required to build this package.
+// swift-tools-version:5.5
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the swift-libp2p open source project
+//
+// Copyright (c) 2022-2025 swift-libp2p project authors
+// Licensed under MIT
+//
+// See LICENSE for license information
+// See CONTRIBUTORS for the list of swift-libp2p project authors
+//
+// SPDX-License-Identifier: MIT
+//
+//===----------------------------------------------------------------------===//
 
 import PackageDescription