ackage libpng12-dev is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package 'libpng12-dev' has no installation candidate
phpunit/phpunit[8.5.8, ..., 8.5.x-dev, 9.3.3, ..., 9.5.x-dev] require ext-dom * -> it is missing from your system. Install or enable PHP's dom extension