Merge pull request #38154 from caesarxuchao/rename-release_1_5

Automatic merge from submit-queue (batch tested with PRs 38154, 38502)

Rename "release_1_5" clientset to just "clientset"

We used to keep multiple releases in the main repo. Now that [client-go](https://github.com/kubernetes/client-go) does the versioning, there is no need to keep releases in the main repo. This PR renames the "release_1_5" clientset to just "clientset", clientset development will be done in this directory.

@kubernetes/sig-api-machinery @deads2k 

```release-note
The main repository does not keep multiple releases of clientsets anymore. Please find previous releases at https://github.com/kubernetes/client-go
```

plugin/pkg/scheduler/algorithmprovider/defaults/BUILD

@@ -34,7 +34,7 @@ go_test(
     deps = [
         "//pkg/api/v1:go_default_library",
         "//pkg/apimachinery/registered:go_default_library",
-        "//pkg/client/clientset_generated/release_1_5:go_default_library",
+        "//pkg/client/clientset_generated/clientset:go_default_library",
         "//pkg/client/restclient:go_default_library",
         "//pkg/runtime:go_default_library",
         "//pkg/util/sets:go_default_library",

plugin/pkg/scheduler/algorithmprovider/defaults/compatibility_test.go

@@ -25,7 +25,7 @@ import (
 
 	"k8s.io/kubernetes/pkg/api/v1"
 	"k8s.io/kubernetes/pkg/apimachinery/registered"
-	clientset "k8s.io/kubernetes/pkg/client/clientset_generated/release_1_5"
+	clientset "k8s.io/kubernetes/pkg/client/clientset_generated/clientset"
 	"k8s.io/kubernetes/pkg/client/restclient"
 	"k8s.io/kubernetes/pkg/runtime"
 	"k8s.io/kubernetes/pkg/util/sets"