Update docker.io/bitnami/kubectl Docker tag to v1.28.6

Signed-off-by: Renovate Bot <tech+renovate@vshn.ch>

Author: vshn-renovate

class/defaults.yml

@@ -236,7 +236,7 @@ parameters:
       kubectl:
         registry: docker.io
         image: bitnami/kubectl
-        tag: '1.28.4@sha256:6485a923f6f4ff3d42d871ce5bd45ee8f25a303c44972a4ad31ddd895082fc22'
+        tag: '1.28.6@sha256:3c94d4fe74b65e6839de46a3eb0f49ca7aabd28cc28ba2e06c0b1e160b88c822'
 
     charts:
       # We do not support helm chart versions older than v1.7.0

tests/golden/cephfs/rook-ceph/rook-ceph/99_cleanup.yaml

@@ -86,7 +86,7 @@ spec:
           env:
             - name: HOME
               value: /home
-          image: docker.io/bitnami/kubectl:1.28.4@sha256:6485a923f6f4ff3d42d871ce5bd45ee8f25a303c44972a4ad31ddd895082fc22
+          image: docker.io/bitnami/kubectl:1.28.6@sha256:3c94d4fe74b65e6839de46a3eb0f49ca7aabd28cc28ba2e06c0b1e160b88c822
           imagePullPolicy: IfNotPresent
           name: cleanup-alertrules
           ports: []

tests/golden/defaults/rook-ceph/rook-ceph/99_cleanup.yaml

@@ -86,7 +86,7 @@ spec:
           env:
             - name: HOME
               value: /home
-          image: docker.io/bitnami/kubectl:1.28.4@sha256:6485a923f6f4ff3d42d871ce5bd45ee8f25a303c44972a4ad31ddd895082fc22
+          image: docker.io/bitnami/kubectl:1.28.6@sha256:3c94d4fe74b65e6839de46a3eb0f49ca7aabd28cc28ba2e06c0b1e160b88c822
           imagePullPolicy: IfNotPresent
           name: cleanup-alertrules
           ports: []

tests/golden/openshift4/rook-ceph/rook-ceph/99_cleanup.yaml

@@ -86,7 +86,7 @@ spec:
           env:
             - name: HOME
               value: /home
-          image: docker.io/bitnami/kubectl:1.28.4@sha256:6485a923f6f4ff3d42d871ce5bd45ee8f25a303c44972a4ad31ddd895082fc22
+          image: docker.io/bitnami/kubectl:1.28.6@sha256:3c94d4fe74b65e6839de46a3eb0f49ca7aabd28cc28ba2e06c0b1e160b88c822
           imagePullPolicy: IfNotPresent
           name: cleanup-alertrules
           ports: []