Sort manifest file paths alphabetically (#14466)

* Sort manifest file paths alphabetically

* Update src/Umbraco.Infrastructure/Manifest/ManifestParser.cs

Co-authored-by: Ronald Barendse <ronald@barend.se>

---------

Co-authored-by: Ronald Barendse <ronald@barend.se>

src/Umbraco.Infrastructure/Manifest/ManifestParser.cs

@@ -250,6 +250,11 @@ public class ManifestParser : IManifestParser
             return Array.Empty<string>();
         }
 
-        return Directory.GetFiles(_path, "package.manifest", SearchOption.AllDirectories);
+        var files = Directory.GetFiles(_path, "package.manifest", SearchOption.AllDirectories);
+
+        // Ensure a consistent, alphabetical sorting of paths, because this is not guaranteed to be the same between file systems or OSes
+        Array.Sort(files);
+
+        return files;
     }
 }