add data-nosnippet attribute to MainLayout razor pages (#51543)

Co-authored-by: Anton Cataldi <anton.cataldi@gmail.com>

Author: abc516

src/Components/Samples/BlazorServerApp/Shared/MainLayout.razor

@@ -14,7 +14,7 @@
     </div>
 
 </div>
-<div id="blazor-error-ui">
+<div id="blazor-error-ui" data-nosnippet>
     An unhandled error has occurred.
     <a href="." class="reload">Reload</a>
     <span class="dismiss">🗙</span>

src/ProjectTemplates/Web.ProjectTemplates/content/BlazorWeb-CSharp/BlazorWeb-CSharp/Components/Layout/MainLayout.razor

@@ -22,7 +22,7 @@
 ##endif*@
 @*#if (UseServer || UseWebAssembly) -->
 
-<div id="blazor-error-ui">
+<div id="blazor-error-ui" data-nosnippet>
     An unhandled error has occurred.
     <a href="." class="reload">Reload</a>
     <span class="dismiss">🗙</span>