build: pass /utf-8 to tinygettext so non-UTF-8 locales can build - #2532

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: chkfung/android-version-actions@v1.2.2. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/