ci: harden dind readiness gate and disable tls startup delay

Jenkinsfile

@@ -27,6 +27,7 @@ spec:
         - --mtu=1400
         - --host=unix:///var/run/docker.sock
         - --host=tcp://0.0.0.0:2375
+        - --tls=false
       volumeMounts:
         - name: dind-storage
           mountPath: /var/lib/docker
@@ -176,12 +177,19 @@ spec:
         container('builder') {
           sh '''
             set -eu
-            for i in $(seq 1 10); do
+            ready=0
+            for i in $(seq 1 90); do
               if docker info >/dev/null 2>&1; then
+                ready=1
                 break
               fi
               sleep 2
             done
+            if [ "${ready}" -ne 1 ]; then
+              echo "docker daemon did not become ready on ${DOCKER_HOST}"
+              docker version || true
+              exit 1
+            fi
             docker buildx use default || docker buildx create --name default --driver docker --use
           '''
         }
@@ -194,6 +202,7 @@ spec:
           sh '''
             set -eu
             VERSION_TAG="$(cut -d= -f2 build.env)"
+            docker info >/dev/null
             for arch in amd64 arm64; do
               docker buildx build \
                 --platform "linux/${arch}" \