git-submodule-deinit

# git-submodule-deinit

deinit
       Unregister the given submodules, i.e. remove the whole submodule.$name section
       from .git/config together with their work tree. Further calls to git submodule
       update, git submodule foreach and git submodule sync will skip any unregistered
       submodules until they are initialized again, so use this command if you don't
       want to have a local checkout of the submodule in your work tree anymore. If
       you really want to remove a submodule from the repository and commit that use
       git-rm(1) instead.

       If --force is specified, the submodule's work tree will be removed even if it
       contains local modifications.