fix(cmake): adopt DFLASH27B_* options left from before the rename - #751

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: ilammy/msvc-dev-cmd@a102174a2b586eec2ea151a69e6fd14404a8ce7c. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/