Merge pull request #62657 from matthyx/master

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Update all script shebangs to use /usr/bin/env interpreter instead of /bin/interpreter

This is required to support systems where bash doesn't reside in /bin (such as NixOS, or the *BSD family) and allow users to specify a different interpreter version through $PATH manipulation.
https://www.cyberciti.biz/tips/finding-bash-perl-python-portably-using-env.html
```release-note
Use /usr/bin/env in all script shebangs to increase portability.
```

Kubernetes-commit: b5f61ac129019d314e473584c1491b7ca62144c7

vendor/k8s.io/api/rbac/v1beta1/generated.proto

@@ -62,6 +62,7 @@ message ClusterRoleBinding {
   optional k8s.io.apimachinery.pkg.apis.meta.v1.ObjectMeta metadata = 1;
 
   // Subjects holds references to the objects the role applies to.
+  // +optional
   repeated Subject subjects = 2;
 
   // RoleRef can only reference a ClusterRole in the global namespace.
@@ -135,6 +136,7 @@ message RoleBinding {
   optional k8s.io.apimachinery.pkg.apis.meta.v1.ObjectMeta metadata = 1;
 
   // Subjects holds references to the objects the role applies to.
+  // +optional
   repeated Subject subjects = 2;
 
   // RoleRef can reference a Role in the current namespace or a ClusterRole in the global namespace.