Release v1.4.0

• (ticaki) rimraf replaced by by internal tool.
• (hombach) change year to 2025
• (hombach) Fix two vulnerabilities
• (hombach) Bump dev dependencies
• (hombach) add tests for node.js 22, remove node 16 tests
• (@GermanBluefox) Added convert command to convert old i18n structure to new one
• (@GermanBluefox) Packages were updated
• (@UncleSamSwiss) Change default path for translation JSON files to admin/i18n/en.json; the old path is still supported for existing repositories