use bitnami/kubectl container image

.gitea/workflows/demo.yaml

@@ -41,6 +41,10 @@ jobs:
   deploy-to-k8s:
     needs: build-and-push
     runs-on: ubuntu-latest
+
+    container:
+      image: bitnami/kubectl:latest
+
     steps:
       - name: Set Kubeconfig
         run: |