Mount volume during docker build so features can use it

I'd like to be able to mount some files which then be later used during feature installation.

Currently I add those files to the host workspace and mount it with `workspaceMount` but obviously it's not available in the feature build step.

I can see that within the BuildKit there is an option that we can leverage:
https://docs.docker.com/reference/dockerfile/#run---mount

Is there any way I can achieve that?