[msbuild] Add CopyToWindows to WriteLinesToFile

Allow remote WriteLinesToFile tasks to copy their generated file back to Windows when requested, while preserving existing local behavior.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot-Session: e9d84281-7deb-4b10-9c48-282faafc8f34

Author: rolfbjarne

msbuild/Xamarin.MacDev.Tasks/MsBuildTasks/WriteLinesToFile.cs

@@ -6,10 +6,19 @@
 namespace Microsoft.Build.Tasks {
 	public class WriteLinesToFile : Microsoft_Build_Tasks_Core::Microsoft.Build.Tasks.WriteLinesToFile, IHasSessionId {
 		public string SessionId { get; set; } = string.Empty;
+		public bool CopyToWindows { get; set; }
+
 		public override bool Execute ()
 		{
-			if (this.ShouldExecuteRemotely (SessionId))
-				return XamarinTask.ExecuteRemotely (this);
+			if (this.ShouldExecuteRemotely (SessionId)) {
+				if (!XamarinTask.ExecuteRemotely (this, out var taskRunner))
+					return false;
+
+				if (CopyToWindows)
+					XamarinTask.CopyFilesToWindowsAsync (this, taskRunner, new [] { File }).Wait ();
+
+				return true;
+			}
 
 			return base.Execute ();
 		}