[Breaking change]: Stop generating runtimeconfig.dev.json by default

[marcpopMSFT]

Description

In the .NET 6 SDK, we stopped generating the runtimeconfig.dev.json file by default as it was not used in most scenarios and added small amounts of performance overhead to find and load that file.

This was changed as of 6.0.100-preview5. We missed it from our breaking change documentation from what I can tell as it shouldn't affect most customers. This did impact a customer who reported this and requested documentation on the change: dotnet/sdk#24427

Version

Other (please put exact version in description textbox)

Previous behavior

Appname.runtimesettings.dev.json would be automatically generated during compile time of the application

New behavior

Appname.runtimesettings.dev.json is no longer generated by default

Type of breaking change

• Binary incompatible: Existing binaries may encounter a breaking change in behavior, such as failure to load/execute or different run-time behavior.
• Source incompatible: Source code may encounter a breaking change in behavior when targeting the new runtime/component/SDK, such as compile errors or different run-time behavior.

Reason for change

This provided a small but measureable performance improvement.
dotnet/sdk#16818
dotnet/sdk#17014

Recommended action

Add <GenerateRuntimeConfigDevFile>true</GenerateRuntimeConfigDevFile> to your project if you still require this file.

Feature area

SDK

Affected APIs

No response