.Net 8 SDK - AddRazorRuntimeCompilation error - Index.cshtml not found

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Describe the bug

We have an .net 6 project that runs MVC, and when we install the .Net 8 SDK on our local machine, and run the project, we get the error:
The view 'Index' was not found. The following locations were searched: /Views/Content/Index.cshtml /Views/Shared/Index.cshtml /Pages/Shared/Index.cshtml

We found that adding

`builder.Services.AddControllersWithViews().AddRazorRuntimeCompilation();`
to program.cs

fixes the issue, but this could potentially break multiple sites, if the server running the site gets the .net 8 SDK

### Expected Behavior

_No response_

### Steps To Reproduce

Have an older .net project either 6 or 7 that runs mvc.
Install .net 8 SDK on local machine
Now the compiler cant find the index.cshtml file.

### Exceptions (if any)

The view 'Index' was not found. The following locations were searched: /Views/Content/Index.cshtml /Views/Shared/Index.cshtml /Pages/Shared/Index.cshtml

### .NET Version

.net 6

### Anything else?

_No response_