support PHP 8

.gitlab-ci.yml

composer.json

src/Row.php

src/Scaffolding/Column.php

src/Scaffolding/PostgresReflector.php

src/Scaffolding/PrivateConstructorDecorator.php

src/Scaffolding/ReconstituteConstructorDecorator.php

src/Scaffolding/TableDecorator.php

src/TableManager.php

src/TypeMapper.php

src/exceptions.php