[Pre4] Blazor inline boot config

[maraf]

In dotnet/runtime#114686 we are inlining boot config into the dotnet.js script.
There won't be an opt-out mechanism (there is at the moment, but I plan to remove it before 10 GA).
The consequences are that there is not separate file containing boot information and so there is no way to programmatically read it. Ideally, we should remove mentions of this concept from the docs, as it should be just implementation detail.

[guardrex]

I think this was addressed by #35176.

I'll use this issue to confirm it or make final updates.