Fix UBI build: add submodules to build-ubi-image - #25

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683, docker/build-push-action@14487ce63c7a62a4a324b0bfb37086795e31c6c1, docker/setup-buildx-action@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/