Add PHP 8.3 compatibility, end PHP 8 and lower support

• adds php8.3 support
• drops php8.0 and lower support
• Upgraded actions/cache to v4 in accordance with notice of v1/v2 package closing down. https://github.blog/changelog/2024-12-05-notice-of-upcoming-releases-and-breaking-changes-for-github-actions/#actions-cache-v1-v2-and-actions-toolkit-cache-package-closing-down