Unclear Documentation: document_root_is_pub no longer relevant for current versions

[CHallski]

Issue in ./help/configuration/reference/config-reference-envphp.md

Optional directory mapping option document_root_is_pub does not have any effect since 2.4.2-p1, but hosts are still referencing this as relevant for later versions because the doc hasn't been updated.

Ref magento/magento2@1ab7166 for this returning true no matter what the config value is.