OCPBUGS-84961: add kubernetes/conformance umbrella suite

Add a kubernetes/conformance suite that aggregates tests from
kubernetes/conformance/parallel and kubernetes/conformance/serial,
enabling `openshift-tests run kubernetes/conformance` to run all
kubernetes conformance tests in a single invocation.

Uses AddGlobalSuite (not AddSuite) so the umbrella starts with zero
qualifiers and inherits exclusively from its children via the
mergeParentQualifiers fixed-point loop in origin. AddSuite would
prepend a catch-all source qualifier that bypasses the exclusion
filters ([Disabled:], [Disruptive], [Slow], etc.) in the child
qualifiers.

Companion to openshift/origin#31261 which adds the Parents field
and mergeParentQualifiers mechanism.

Upstream: <carry>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: not-stbenjam

openshift-hack/cmd/k8s-tests-ext/k8s-tests.go

@@ -70,9 +70,14 @@ func main() {
 		Qualifiers: []string{withExcludedTestsFilter(`(name.contains('[Serial]') || labels.exists(l, l == '[Serial]')) && labels.exists(l, l == "Conformance")`)},
 	})
 
+	kubeTestsExtension.AddGlobalSuite(e.Suite{
+		Name: "kubernetes/conformance",
+	})
+
 	kubeTestsExtension.AddSuite(e.Suite{
 		Name: "kubernetes/conformance/parallel",
 		Parents: []string{
+			"kubernetes/conformance",
 			"openshift/conformance/parallel",
 		},
 		Qualifiers: []string{withExcludedTestsFilter(`(!name.contains('[Serial]') && !labels.exists(l, l == '[Serial]'))`)},
@@ -81,6 +86,7 @@ func main() {
 	kubeTestsExtension.AddSuite(e.Suite{
 		Name: "kubernetes/conformance/serial",
 		Parents: []string{
+			"kubernetes/conformance",
 			"openshift/conformance/serial",
 		},
 		Qualifiers: []string{withExcludedTestsFilter(`(name.contains('[Serial]') || labels.exists(l, l == '[Serial]'))`)},