Remove unnecessary ETCD_UNSUPPORTED_ARCH for arm64

we should only use this env var for `arm`, since `arm64` is fully
supported by etcd folks, let us drop this!

(ex - https://github.com/etcd-io/etcd/releases/tag/v3.5.6)

ppc64le comment should be dropped as well

Signed-off-by: Davanum Srinivas <davanum@gmail.com>

test/integration/framework/etcd.go

@@ -24,7 +24,6 @@ import (
 	"net"
 	"os"
 	"os/exec"
-	"runtime"
 	"strings"
 	"syscall"
 	"time"
@@ -64,10 +63,6 @@ func getAvailablePort() (int, error) {
 // startEtcd executes an etcd instance. The returned function will signal the
 // etcd process and wait for it to exit.
 func startEtcd() (func(), error) {
-	if runtime.GOARCH == "arm64" {
-		os.Setenv("ETCD_UNSUPPORTED_ARCH", "arm64")
-	}
-
 	etcdURL := env.GetEnvAsStringOrFallback("KUBE_INTEGRATION_ETCD_URL", "http://127.0.0.1:2379")
 	conn, err := net.Dial("tcp", strings.TrimPrefix(etcdURL, "http://"))
 	if err == nil {