Fix return type to task

Author: davidkallesen

src/Atc.CodingRules.Updater/FileHelper.cs

@@ -2,11 +2,12 @@ namespace Atc.CodingRules.Updater;
 
 public static class FileHelper
 {
+    [SuppressMessage("Performance", "CA1819:Properties should not return arrays", Justification = "OK.")]
     public static string[] LineBreaks => Helpers.FileHelper.LineBreaks;
 
     public static string ReadAllText(FileInfo file) => Helpers.FileHelper.ReadAllText(file);
 
-    public static void WriteAllTextAsync(FileInfo file, string content) => Helpers.FileHelper.WriteAllTextAsync(file, content);
+    public static Task WriteAllTextAsync(FileInfo file, string content) => Helpers.FileHelper.WriteAllTextAsync(file, content);
 
     public static Collection<FileInfo> SearchAllForElement(
         DirectoryInfo projectPath,