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>.
add PST to main SECURITY_CONTACTS as formality
Add the Product Security Team as the security contacts for the main
repository and they can use the OWNERS files in each subsystem/dir to find
the correct owners.
cc @liggitt @cjcullen @tallclair @philips
```release-note
NONE
```
closes#64265
Signed-off-by: Jess Frazelle <acidburn@microsoft.com>
Kubernetes-commit: 5da925ad4fd070e687dc5255c177d5e7d542edd7
