fix: use nc TCP check for dind readiness instead of docker info

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

runner/deployment.yaml

@@ -24,7 +24,7 @@ spec:
       containers:
         - name: runner
           image: gitea/act_runner:latest
-          command: ["sh", "-c", "until docker info > /dev/null 2>&1; do echo 'waiting for dind...'; sleep 2; done && exec /usr/local/bin/act_runner daemon"]
+          command: ["sh", "-c", "until nc -z localhost 2375 2>/dev/null; do echo 'waiting for dind...'; sleep 2; done && exec /usr/local/bin/act_runner daemon"]
           resources:
             requests:
               cpu: 100m