Release machine-solidity-step v0.15.0 - #102

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: foundry-rs/foundry-toolchain@50d5a8956f2e319df19e6b57539d7e2acb9f8c1e. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/