We create a temporary directory for holding a clone but we never clean it
up. Fix this by using a context manager areound the temporary directory.
This resolves a buildup of tmp directories in DL_DIR in builds.
(Bitbake rev: 1a62878a790ed9630d5ca2fa099d1604540e153a)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Paul Barker <paul@pbarker.dev>