fix: skip fzf launch in kubens when no contexts exist in kubeconfig

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/release.yml

@@ -24,7 +24,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout
-      uses: actions/checkout@v6
+      uses: actions/checkout@v4
     - run: git fetch --tags
     - name: Setup Go
       uses: actions/setup-go@v6