Builds from source repositories: control submodule pull

Lately I've been building most packages directly from their source repositories. Not best-practice perhaps, but in this case a necessity.

Adding an entry to rosdistro_additional_recipes.yaml is easy enough and works well.

Some of those repositories however use submodules, and similar to the motivation given in prefix-dev/rattler-build#2107 it would be nice if we could prevent those submodules from getting pulled: they may not be necessary for the build of a particular package from a set of packages in a (mono)repository or undesired for other reasons.

prefix-dev/rattler-build#2158 seems to have added a way to make rattler-build ignore them, but I couldn't find a way for Vinca to generate recipes that added the submodules: false key-value pair to the source dict.

Would there be interest in adding this? If so, what would be the nicest way of doing that?

Start by tracing how rosdistro_additional_recipes.yaml entries are turned into generated recipe source dictionaries, then compare the requested behavior with rattler-build#2158. Done means Vinca can express the option and generated recipes include submodules: false when requested, without changing existing recipes by default.