Bus_SPI: initialize spi_bus_config_t::dma_burst_size for ESP-IDF 6.1 - #280

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/