Remove invalid asp-route-returnUrl attribute from Blazor Register template (#62443)

* Initial plan for issue

* Remove invalid asp-route-returnUrl attribute from Blazor Register template

Co-authored-by: MackinnonBuck <[email protected]>

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: MackinnonBuck <[email protected]>

Author: Copilot

src/ProjectTemplates/Web.ProjectTemplates/content/BlazorWeb-CSharp/BlazorWeb-CSharp/Components/Account/Pages/Register.razor

@@ -22,7 +22,7 @@
 <div class="row">
     <div class="col-lg-6">
         <StatusMessage Message="@Message" />
-        <EditForm Model="Input" asp-route-returnUrl="@ReturnUrl" method="post" OnValidSubmit="RegisterUser" FormName="register">
+        <EditForm Model="Input" method="post" OnValidSubmit="RegisterUser" FormName="register">
             <DataAnnotationsValidator />
             <h2>Create a new account.</h2>
             <hr />