git: Update local_checkout to be in sync with community's
git: Update local_checkout to be in sync with community's

Instead of the previous implementation, use the community's one
used in https://gitlab.freedesktop.org/gstreamer/cerbero until
commit 4b4519b9 just for the local_checkout function.

Issue: OCP-1914

fluendo/cerbero,fluendo/cerbero,fluendo/cerbero,fluendo/cerbero,fluendo/cerbero