.NET 8: Tidy required .json assets for apps

[richlander]

.NET apps have two .json files that are not important to be either loose assets or in existence at all in some scenarios.

Example:

root@d17c4ab3cf2c:/# dotnet new console -o app
The template "Console Application" was created successfully.

Processing post-creation actions...
Running 'dotnet restore' on app/app.csproj...
  Determining projects to restore...
  Restored /app/app.csproj (in 35 ms).
Restore succeeded.

root@d17c4ab3cf2c:/# cd app
root@d17c4ab3cf2c:/app# dotnet build
Microsoft (R) Build Engine version 17.0.0-preview-21302-02+018bed83d for .NET
Copyright (C) Microsoft Corporation. All rights reserved.

  Determining projects to restore...
  All projects are up-to-date for restore.
  You are using a preview version of .NET. See: https://aka.ms/dotnet-core-preview
  app -> /app/bin/Debug/net6.0/app.dll

Build succeeded.
    0 Warning(s)
    0 Error(s)

Time Elapsed 00:00:00.58
root@d17c4ab3cf2c:/app# find . | grep Debug | grep .json
./bin/Debug/net6.0/app.runtimeconfig.json
./bin/Debug/net6.0/app.deps.json

Proposal:

• Embed runtimeconfig.json for all apps, possibly in the app host.
• Do not produce deps.json for RID-specific apps, at least by default.

This would result in .NET apps being two files by default (not counting the PDB). It would bring us much closer to the one-file experience we had with .NET Framework, by default. If folks wanted just one file, they could opt for framework-dependent single file.

[dotnet-issue-labeler]

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

[Nirmal4G]

Embed runtimeconfig.json for all apps, possibly in the app host.

Since the dotnet host loads both files, why not merge the schema into a single file and embed it in the App lib itself? We could call it app.run.json. If user wants to override then they can place the same file ouside with overrides and have those take effect.