According to composer.json, PHP 7.4 still is officially supported:
However PR #1802 added an explicit implementation of the \Stringable to various classes. This interface only exists as of PHP 8. The library is broken with PHP 7.4 since then:
Error: Interface 'Stringable' not found in /home/runner/work/*snip*/vendor/webonyx/graphql-php/src/Type/Definition/Type.php:12
According to composer.json, PHP 7.4 still is officially supported:
graphql-php/composer.json
Line 12 in b2d7b74
However PR #1802 added an explicit implementation of the
\Stringableto various classes. This interface only exists as of PHP 8. The library is broken with PHP 7.4 since then: