package/setools: bump to 4.3.0

package/setools: bump to 4.3.0

setools is no longer hosted on https://github.com/TresysTechnology/setools/.
Update the source location to its new home,
https://github.com/SELinuxProject/setools/.

Refresh patches 0001-remove-werror-flag-from-setup.patch and
0002-Do-not-export-use-setools.InfoFlowAnalysis-and-setoo.patch for
4.3.0 and remove patch 0003-setup.py-drop-path-prefix-from-man-install.patch
that is now upstream.

Add a new dependency on host-python-cython, as setup.py now depends on
it.

Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>