skip etcd unit tests on non fully supported architectures

etcd only fully supports linux && amd64, the other architectures
and OS are only guaranteed to build, see:

https://etcd.io/docs/v3.5/op-guide/supported-platform/#support-tiers

Skip the test that use etcd on not well supported environment to
guarantee the stability of the test.

test/e2e/framework/internal/unittests/cleanup/cleanup_test.go

@@ -1,3 +1,5 @@
+//go:build linux && amd64
+
 /*
 Copyright 2022 The Kubernetes Authors.
 
@@ -14,6 +16,9 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+// This test uses etcd that is only fully supported for AMD64 and Linux
+// https://etcd.io/docs/v3.5/op-guide/supported-platform/#support-tiers
+
 package cleanup
 
 import (
@@ -42,11 +47,6 @@ import (
 //
 //
 //
-//
-//
-//
-//
-//
 // This must be line #50.
 
 var _ = ginkgo.Describe("e2e", func() {