app_python3: bump to 3.12 for el8/el9

(cherry picked from commit 4d87f29248d36d873784827204f272116050343d)

pkg/kamailio/obs/kamailio.spec

@@ -847,9 +847,9 @@ Requires:   python2, kamailio = %ver
 BuildRequires:  python2, python2-devel
 %endif
 %if %{with python3}
-%if 0%{?rhel} == 8
-Requires:   python39, kamailio = %ver
-BuildRequires:  python39, python39-devel
+%if 0%{?rhel} == 8 || 0%{?rhel} == 9
+Requires:   python3.12, kamailio = %ver
+BuildRequires:  python3.12, python3.12-devel
 %else
 Requires:   python3, kamailio = %ver
 BuildRequires:  python3, python3-devel
@@ -1236,7 +1236,7 @@ make every-module skip_modules="app_mono db_cassandra db_oracle iptrtpproxy \
     FREERADIUS=1 \
 %endif
 %if 0%{?rhel} >= 8
-    PYTHON3=python3.9 \
+    PYTHON3=python3.12 \
 %endif
     group_include="kstandard kautheph kberkeley kcarrierroute \
 %if %{with cnxcc}