typo: Fix typo in psfile.yaml release note (#25858)
typo: Fix typo in psfile.yaml release note (#25858)

In #25627 there was a typo of `istioctlS` instead of `istioctl`.  This
resolves that as well as ensuring the file ends with a newline (as all
of the other release notes do).
istio/istio,istio/istio,istio/istio,istio/istio,istio/istio