Maintenance release: PHP 8.x Compatibility

What's new:

• Remove any deprecated warning for PHP 8.x
• Using PHP Intl instead of strftime to localize the date format
• Language improvements. Credit @mieszkou @lotfihamid @kshman @bartokopec @Eliastik @StefanosSfaellos @eagleman
• A few improvements. Credit @MCUmbrella @dolibarr95 @bttrx

After updating, please choose your blog time format in admin/config