ci: 将 Redis 依赖替换为 Valkey

SearxNG 服务现在依赖于 Valkey 而不是 Redis，以提升性能和兼容性

searxng/stack.yml

@@ -19,7 +19,7 @@ services:
     container_name: searxng
     restart: unless-stopped
     depends_on:
-      - redis
+      - valkey
     environment:
       - SEARXNG_BASE_URL=https://${SEARXNG_HOSTNAME:-localhost}/
       - UWSGI_WORKERS=${SEARXNG_UWSGI_WORKERS:-4}