Introduce a setting for automatically disabling the implicit restore

[baronfel]

Is your feature request related to a problem? Please describe.

Some users express annoyance that the implicit restore occurs for build and build-related commands, and must be explicitly disabled with each command via the --no-restore CLI flag. Those users would prefer to manage restores explicitly and not pay the price for the restore on each subsequent step.

Similar logic follows for situations where the build is implicit, like dotnet run - these should be as fast as possible in the minds of these users and so implicit behaviors should be disabled by default, requiring explicit orchestration.

Describe the solution you'd like

We should have some centralized preference or configuration that lets a user opt out of implicit restore and all build-triggering commands should adhere to that preference

Additional context

• BlueSky discussion on run overhead
• .NET 8: MSBuild improvements for containers #26249

[Evangelink]

The same applies for dotnet test where outside of demos you would "always" want to --no-build --no-restore.

cc @MarcoRossignoli