install kubectl if not available

.gitea/workflows/docker-publish.yml

@@ -78,11 +78,7 @@ jobs:
 
       - name: Install kubectl
         run: |
-          curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"
-          chmod +x kubectl
-          mkdir -p "$HOME/bin"
-          mv kubectl "$HOME/bin/"
-          echo "$HOME/bin" >> $GITHUB_PATH
+          apk add --no-cache kubectl
 
       - name: Setup kubectl
         run: |