Clean up obsolete APIs in MVC

[captainsafia]

Part of #27529.

Summary of Changes

• ObjectResultExecutor constructor that provide a null MVCOptions was removed since that will eventually trigger a null-ref in the code.
• Remove GetFileStream API in PhysicalFileResultExecutor and VirtualFileResultExecutor because codepath is no-longer invoked.
• Remove AllowShortCircuitingValidationWhenNoValidatorsArePresent in ValidationVisitor because value no-ops and has been obsolete since 3.0.
• Remove RazorViewAttribute and RazorPageAttribute and instances of use since they are deprecated in favor of newer APIs.
• Remove unnecessary constructor for ViewComponentResultExecutor which set a null WriterFactory since the value was overridden anyways.
• Obsolete CompatabilityVersion type.

[ghost]

Thank you for submitting this for API review. This will be reviewed by @dotnet/aspnet-api-review at the next meeting of the ASP.NET Core API Review group. Please ensure you take a look at the API review process documentation and ensure that:

• The PR contains changes to the reference-assembly that describe the API change. Or, you have included a snippet of reference-assembly-style code that illustrates the API change.
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[captainsafia]

@dotnet/aspnet-api-review This is good for review. I've removed references to SetCompatibilityVersion per our discussion.

[ghost]

Hello @pranavkm!

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