Is your feature request related to a problem? Please describe.
There exist repositories of dart code that contain pubspec.yaml files, but where it is almost never the right choice to actually run dart pub get. An example of this is the Dart SDK repository, directories under pkg: https://github.com/dart-lang/sdk/tree/main/pkg. Some of these directories contain pubspec.yaml files, but under normal circumstances the workflow for editing them depends on externally constructed .dart_tool directories checked in at the top level which would be overridden by pub get. Some contain pubspec.yaml files that do not reference real packages, as well.

In addition, it can be desirable to manually edit and control .dart_tool directories while developing. Without a way to shut off modifying them via dart pub get, those workflows are disallowed.

Describe the solution you'd like
A configuration option that allows the user to stop dart pub get runs from happening when using the automatic Run | Debug options for tests and main() functions. As well, if pub get fails, the user could be prompted to ignore this. This could be implemented with a simple on/off switch, or a configuration option to change what is run when fetching packages so Dart could be replaced with /bin/true. Other possibilities abound.

Describe alternatives you've considered
-- see above --

Additional context
IntelliJ allows you to semi-permanently ignore pub get failures when they occur, which is compatible with my workflow.