PHP2Shell on PHP 8: docker build --pull succeeded and PHP is still 8.2.29

php:8.2-fpm-bullseye has been frozen at PHP 8.2.29 since 5 August 2025, so --pull on that tag downloads a vulnerable image and reports success. Five measured ways a Docker tag misleads you about the PHP version inside it, and what to use instead on 8.2, 8.4 and EOL 8.0.