Need add python3-git to buildtools-tarball for the py3 build, and the
dependencies chain is:
python3-git -> python3-gitdb -> python3-smmap
(From OE-Core rev: 762c280259b90d2cb827b8f8dc62490e36bd7df8)
Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>