What problem is this issue looking to solve?

A pipeline that builds all the listed PHP versions would pave the way to one-click switching of the PHP version:

How does this issue proposes to solve it?

The technical foundation was shipped in 45ba8ce. Since that commit, the docker build process can be build a specific PHP version as follows:

docker build . --no-cache --tag=wasm-wordpress-php-builder --build-arg PHP_VERSION="8.0.29" --build-arg VRZNO_FLAG="--disable-vrzno"

I confirmed it works with 7.0.0, 7.0.24 and even 8.0.29 when vrzno is disabled. It may break for versions that are not compatible with the PHP patches shipped in this repo.