auto-docs: Update K8s acceptance tests

Author: vbotbuildovich

modules/manage/examples/kubernetes/upgrade.feature

@@ -0,0 +1,47 @@
+Feature: Upgrading redpanda
+  @skip:gke @skip:aks @skip:eks @skip:k3d
+  Scenario: Redpanda upgrade from 25.2.11
+    Given I apply Kubernetes manifest:
+    """
+    ---
+    apiVersion: cluster.redpanda.com/v1alpha2
+    kind: Redpanda
+    metadata:
+      name: cluster-upgrade
+    spec:
+      clusterSpec:
+        image:
+          repository: redpandadata/redpanda
+          tag: v25.2.11
+        console:
+          enabled: false
+        statefulset:
+          replicas: 3
+          sideCars:
+            image:
+              tag: dev
+              repository: localhost/redpanda-operator
+    """
+    And cluster "cluster-upgrade" should be stable with 3 nodes
+    Then I apply Kubernetes manifest:
+    """
+    ---
+    apiVersion: cluster.redpanda.com/v1alpha2
+    kind: Redpanda
+    metadata:
+      name: cluster-upgrade
+    spec:
+      clusterSpec:
+        image:
+          repository: redpandadata/redpanda-unstable
+          tag: v25.3.1-rc4
+        console:
+          enabled: false
+        statefulset:
+          replicas: 3
+          sideCars:
+            image:
+              tag: dev
+              repository: localhost/redpanda-operator
+    """
+    And cluster "cluster-upgrade" should be stable with 3 nodes