PHP 8 compatibility

[mstrelan]

composer/semver 1.5.1 requires php (^5.3.2 || ^7.0)
doctrine/annotations v1.4.0 requires php (^5.6 || ^7.0)
doctrine/cache v1.6.2 requires php (~5.5|~7.0)
doctrine/collections v1.4.0 requires php (^5.6 || ^7.0)
doctrine/common v2.7.3 requires php (~5.6|~7.0)
doctrine/inflector v1.2.0 requires php (^7.0)
drupal/core 8.9.13 requires php (^7.0.8)
laminas/laminas-diactoros 1.8.7p2 requires php (^5.6 || ^7.0)
laminas/laminas-escaper 2.6.1 requires php (^5.6 || ^7.0)
laminas/laminas-feed 2.12.2 requires php (^5.6 || ^7.0)
laminas/laminas-stdlib 3.2.1 requires php (^5.6 || ^7.0)
laminas/laminas-zendframework-bridge 1.0.4 requires php (^5.6 || ^7.0)
paragonie/random_compat v9.99.99 requires php (^7)
phar-io/manifest 1.0.3 requires php (^5.6 || ^7.0)
phar-io/version 2.0.1 requires php (^5.6 || ^7.0)
phpunit/php-code-coverage 6.1.4 requires php (^7.1)
phpunit/phpunit 7.5.20 requires php (^7.1)
sebastian/global-state 2.0.0 requires php (^7.0)
symfony-cmf/routing 1.4.1 requires php (^5.3.9|^7.0)
symfony/psr-http-message-bridge v1.1.2 requires php (^5.3.3 || ^7.0)
typo3/phar-stream-wrapper v3.1.4 requires php (^7.0)