Update Blazor forms enum in example code (#20316)

Author: guardrex

aspnetcore/blazor/forms-validation.md

@@ -789,7 +789,7 @@ public Engine? Engine { get; set; } = null;
 Add the following `enums` to the app. Create a new file to hold the `enums` or add the `enums` to the `Starship.cs` file. Make the `enums` accessible to the `Starship` model and the *Starfleet Starship Database* form:
 
 ```csharp
-public enum Manufacturer { SpaceX, NASA, ULA, Virgin, Unknown }
+public enum Manufacturer { SpaceX, NASA, ULA, VirginGalactic, Unknown }
 public enum Color { ImperialRed, SpacecruiserGreen, StarshipBlue, VoyagerOrange }
 public enum Engine { Ion, Plasma, Fusion, Warp }
 ```