Re-add SPM support

Author: stuartmorgan-g

packages/file_selector/file_selector_ios/ios/file_selector_ios/Package.swift

@@ -0,0 +1,31 @@
+// swift-tools-version: 5.9
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import PackageDescription
+
+let package = Package(
+  name: "file_selector_ios",
+  platforms: [
+    .iOS("12.0")
+  ],
+  products: [
+    .library(name: "file-selector-ios", targets: ["file_selector_ios"])
+  ],
+  dependencies: [],
+  targets: [
+    .target(
+      name: "file_selector_ios",
+      dependencies: [],
+      resources: [
+        .process("Resources")
+      ],
+      cSettings: [
+        .headerSearchPath("include/file_selector_ios")
+      ]
+    )
+  ]
+)