Enable CI gating

Set up CI gating for Fedora Rawhide, and RHEL-9.

gating.yaml

@@ -0,0 +1,13 @@
+--- !Policy
+product_versions:
+  - fedora-*
+decision_context: bodhi_update_push_stable
+subject_type: koji_build
+rules:
+  - !PassingTestCaseRule {test_case_name: baseos-qe.koji-build.scratch-build.validation}
+--- !Policy
+product_versions:
+  - rhel-9
+decision_context: osci_compose_gate
+rules:
+  - !PassingTestCaseRule {test_case_name: baseos-ci.brew-build.tier1.functional}