docs: clarify that PodSecurityPolicy is now deprecated (cloudnative…

…-pg#3992)

Addressing `PodSecurityPolicy` removal in Kubernetes v1.25. Explaining
our reasons for keeping this section for now, even though it's slated
for removal in the near future.

Closes cloudnative-pg#3991

Signed-off-by: Jonathan Gonzalez V <jonathan.gonzalez@enterprisedb.com>
Signed-off-by: Gabriele Bartolini <gabriele.bartolini@enterprisedb.com>
Co-authored-by: Gabriele Bartolini <gabriele.bartolini@enterprisedb.com>

.wordlist-en-custom.txt

@@ -279,6 +279,7 @@ PodAntiAffinityType
 PodDisruptionBudget
 PodMeta
 PodMonitor
+PodSecurityPolicy
 PodSpec
 PodStatus
 PodTemplateSpec

docs/src/security.md

@@ -215,6 +215,13 @@ CloudNativePG.
 
 ### Pod Security Policies
 
+!!! Important
+    Starting from Kubernetes v1.21, the use of `PodSecurityPolicy` has been
+    deprecated, and as of Kubernetes v1.25, it has been completely removed. Despite
+    this deprecation, we acknowledge that the operator is currently undergoing
+    testing in older and unsupported versions of Kubernetes. Therefore, this
+    section is retained for those specific scenarios.
+
 A [Pod Security Policy](https://kubernetes.io/docs/concepts/policy/pod-security-policy/)
 is the Kubernetes way to define security rules and specifications that a pod needs to meet
 to run in a cluster.