Update docker.io/bitnami/kubectl Docker tag to v1.31.4

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

Author: vshn-renovate

class/defaults.yml

@@ -19,7 +19,7 @@ parameters:
       kubectl:
         registry: docker.io
         image: bitnami/kubectl
-        tag: "1.28.15"
+        tag: "1.31.4"
 
     storage:
       persistence: true

tests/golden/oidc/oidc/oidc/10_cluster.yaml

@@ -605,7 +605,7 @@ spec:
               value: /export
             - name: VCLUSTER_SERVER_URL
               value: https://oidc:443
-          image: docker.io/bitnami/kubectl:1.28.15
+          image: docker.io/bitnami/kubectl:1.31.4
           imagePullPolicy: IfNotPresent
           name: oidc-synthesize
           ports: []

tests/golden/openshift/openshift/openshift/10_cluster.yaml

@@ -703,7 +703,7 @@ spec:
               value: syn-openshift
             - name: VCLUSTER_STS_NAME
               value: openshift
-          image: docker.io/bitnami/kubectl:1.28.15
+          image: docker.io/bitnami/kubectl:1.31.4
           imagePullPolicy: IfNotPresent
           name: openshift
           ports: []