fix discard syntax

Author: mvdgun

FileSystem.Adapters.Sftp/src/SftpAdapter.cs

@@ -180,7 +180,7 @@ public override async Task<byte[]> ReadFileAsync(string virtualPath, Cancellatio
                 using var fileStream = client.OpenRead(GetPath(virtualPath));
                 var fileContents = new byte[fileStream.Length];
 
-                var _ = await fileStream.ReadAsync(fileContents, 0, (int) fileStream.Length, cancellationToken);
+                _ = await fileStream.ReadAsync(fileContents, 0, (int) fileStream.Length, cancellationToken);
 
                 return fileContents;
             }

FileSystem/src/Adapters/LocalAdapter.cs

@@ -151,7 +151,7 @@ public override async Task<byte[]> ReadFileAsync(string virtualPath, Cancellatio
             using var fileStream = new FileStream(GetPath(virtualPath), FileMode.Open);
             var fileContents = new byte[fileStream.Length];
 
-            var _ = await fileStream.ReadAsync(fileContents, 0, (int) fileStream.Length, cancellationToken);
+            _ = await fileStream.ReadAsync(fileContents, 0, (int) fileStream.Length, cancellationToken);
 
             return fileContents;
         }