It contains the feature required to get a directory traversal.

With a traditional walk, `.git` will be picked up, and so will be
ignored directories. This commit also doesn't give submodules special
treatment - instead it just tries to open directories as repositories,
or walks them if that fails.

This is the case for the git2 implementation naturally, but as
`gitoxide` doesn't yet have a dirwalk iterator, it's much
less intuitive here.

* remove renovate group as it's not needed anymore
* repository discovery will open with isolation

…picked up

It's not necessary, and adds noise.

Co-authored-by: Arlo Siemsen <arkixml@gmail.com>

Top-level pathspecs are needed to assure they are not affected by
the CWD. The trailing `/` in `'target` is needed to assure excluded
items are in a folder, and that only entries in that folder are extracted
from the index.