docs: update copyright year to 2025}
* Update copyright year from 2024 to 2025 in INSTALL.md * Update copyright year in README.md * Update copyright year in artifacts/php-7.2-ubuntu.md * Update copyright year in artifacts/screenshots.md * Update copyright year in change-break.md * Update copyright year in change-log.2019.md * Update copyright year in change-log.2021.md * Update copyright year in change-log.2023.md * Update copyright year in change-log.2024.md * Update copyright year and format in change-log.md * Update package version and copyright year in package.json * Update copyright year in src/Gitter/Util/DateTime.php * Update copyright year in todo.md