Razor should warn about the use of runtime compilation

[chsienki]

When targeting net10 we should issue a warning if the user is also using the runtime compilation package. Runtime compilation does not support the new C# based lexer which means things that compile in the IDE/command line may fail to compile when runtime compilation kicks in.

[DamianEdwards]

FYI @danroth27

[danroth27]

Yup, we've discussed this previously. There are already cases where this can happen today. Razor Runtime Compilation is pinned to a pretty old version of C#.