use official install steps

.woodpecker/ci.yaml

@@ -11,10 +11,8 @@ steps:
       - update-ca-certificates
       - |
         echo "Installing kubectl..."
-        KUBECTL_VERSION=$(curl -sL https://dl.k8s.io/release/stable.txt | tr -d '\n')
-        curl -LO --fail https://dl.k8s.io/release/${KUBECTL_VERSION}/bin/linux/amd64/kubectl
-        chmod +x kubectl
-        mv kubectl /usr/local/bin/
+        curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"
+        install -o root -g root -m 0755 kubectl /usr/local/bin/kubectl
       - |
         echo "Validating Kubernetes manifests with kubectl dry-run..."
         for file in $(find . -maxdepth 1 -type f \( -name '*.yaml' -o -name '*.yml' \)); do