build: Remove release from version req and python define changes.

Our OBS does not utilize release in version.

Define python3_sitearch only if it is not defined.

rpm/libselinux.spec

@@ -20,13 +20,15 @@
 # TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 # SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
-%define libsepolver 2.8-1
+%define libsepolver 2.8
 # our old rpm doesn't yet support the rundir macro
 %if ! %{defined _rundir}
 %define _rundir %{_localstatedir}/run
 %endif
 
+%if ! %{defined python3_sitearch}
 %define python3_sitearch /%{_libdir}/python3.?/site-packages
+%endif
 
 Summary: SELinux library and simple utilities
 Name: libselinux