Niklas Gehlen

Implement ability to load images by default in non-Docker build drivers.

5

This eases build driver migrations, as it allows aligning the default behavior. See also https://docs.docker.com/build/drivers/

Consider already existing images as successful pulls.

1

Fixes #2010 Status can be found in upstream moby: https://github.com/moby/moby/blob/f3f20c3a862ff90c7e7b0ee07dabe2176ed0a170/plugin/fetch_linux.go#L224

Lock store writer per digest and writer root.

1

This allows multiple writers to not lock if they operate in different roots. See also https://github.com/moby/buildkit/issues/3270#issuecomment-1323606958