fedora rawhide: Temporarily disable failing DNS tests

Some DNS tests have been disabled for Fedora latest, but not for Fedora
Rawhide. Therefore these tests are filin still in nighty:

- dnsforwardzone
- test_dnsconfig_forwarders_ports

tests/azure/templates/variables_fedora-rawhide.yaml

@@ -15,5 +15,7 @@ variables:
   empty: true
   # ipa_enabled_modules: >-
   # ipa_enabled_tests: >-
-  # ipa_disabled_modules: >-
-  # ipa_disabled_tests: >-
+  ipa_disabled_modules: >-
+    dnsforwardzone,
+  ipa_disabled_tests: >-
+    test_dnsconfig_forwarders_ports